fix(core,protocol): simplify store_protocol and add download size cap

- store_protocol: always write to shared Arc<Mutex<Option<ProtocolClient>>>; the FileTransferService holds the same Arc so it sees updates automatically - read_download_bytes: reject downloads exceeding 10 MB to prevent malicious servers from causing OOM
feat(core,bridge): add get_icon with coalescing and negative cache
2026-06-10 09:36:27 +09:00 · 2026-06-10 07:38:21 +09:00 · 2026-06-10 07:24:08 +09:00 · 2026-06-10 07:09:55 +09:00 · 2026-06-10 07:09:47 +09:00 · 2026-06-10 07:09:40 +09:00
18 changed files with 4376 additions and 58 deletions
@@ -148,12 +148,111 @@ version = "0.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "435a87a52755b8f27fcf321ac4f04b2802e337c8c4872923137471ec39c37532"
 dependencies = [
- "event-listener",
+ "event-listener 5.4.1",
 "event-listener-strategy",
 "futures-core",
 "pin-project-lite",
 ]
 [[package]]
 name = "async-channel"
 version = "1.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "81953c529336010edd6d8e358f886d9581267795c61b19475b71314bffa46d35"
 dependencies = [
 "concurrent-queue",
 "event-listener 2.5.3",
 "futures-core",
 ]
 [[package]]
 name = "async-channel"
 version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "924ed96dd52d1b75e9c1a3e6275715fd320f5f9439fb5a4a11fa51f4221158d2"
 dependencies = [
 "concurrent-queue",
 "event-listener-strategy",
 "futures-core",
 "pin-project-lite",
 ]
 [[package]]
 name = "async-executor"
 version = "1.14.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c96bf972d85afc50bf5ab8fe2d54d1586b4e0b46c97c50a0c9e71e2f7bcd812a"
 dependencies = [
 "async-task",
 "concurrent-queue",
 "fastrand",
 "futures-lite",
 "pin-project-lite",
 "slab",
 ]
 [[package]]
 name = "async-global-executor"
 version = "2.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "05b1b633a2115cd122d73b955eadd9916c18c8f510ec9cd1686404c60ad1c29c"
 dependencies = [
 "async-channel 2.5.0",
 "async-executor",
 "async-io",
 "async-lock",
 "blocking",
 "futures-lite",
 "once_cell",
 ]
 [[package]]
 name = "async-io"
 version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "456b8a8feb6f42d237746d4b3e9a178494627745c3c56c6ea55d92ba50d026fc"
 dependencies = [
 "autocfg",
 "cfg-if",
 "concurrent-queue",
 "futures-io",
 "futures-lite",
 "parking",
 "polling",
 "rustix",
 "slab",
 "windows-sys 0.61.2",
 ]
 [[package]]
 name = "async-lock"
 version = "3.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "290f7f2596bd5b78a9fec8088ccd89180d7f9f55b94b0576823bbbdc72ee8311"
 dependencies = [
 "event-listener 5.4.1",
 "event-listener-strategy",
 "pin-project-lite",
 ]
 [[package]]
 name = "async-process"
 version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fc50921ec0055cdd8a16de48773bfeec5c972598674347252c0399676be7da75"
 dependencies = [
 "async-channel 2.5.0",
 "async-io",
 "async-lock",
 "async-signal",
 "async-task",
 "blocking",
 "cfg-if",
 "event-listener 5.4.1",
 "futures-lite",
 "rustix",
 ]
 [[package]]
 name = "async-recursion"
 version = "1.1.1"
@@ -165,6 +264,57 @@ dependencies = [
 "syn",
 ]
 [[package]]
 name = "async-signal"
 version = "0.2.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "52b5aaafa020cf5053a01f2a60e8ff5dccf550f0f77ec54a4e47285ac2bab485"
 dependencies = [
 "async-io",
 "async-lock",
 "atomic-waker",
 "cfg-if",
 "futures-core",
 "futures-io",
 "rustix",
 "signal-hook-registry",
 "slab",
 "windows-sys 0.61.2",
 ]
 [[package]]
 name = "async-std"
 version = "1.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2c8e079a4ab67ae52b7403632e4618815d6db36d2a010cfe41b02c1b1578f93b"
 dependencies = [
 "async-channel 1.9.0",
 "async-global-executor",
 "async-io",
 "async-lock",
 "async-process",
 "crossbeam-utils",
 "futures-channel",
 "futures-core",
 "futures-io",
 "futures-lite",
 "gloo-timers",
 "kv-log-macro",
 "log",
 "memchr",
 "once_cell",
 "pin-project-lite",
 "pin-utils",
 "slab",
 "wasm-bindgen-futures",
 ]
 [[package]]
 name = "async-task"
 version = "4.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b75356056920673b02621b35afd0f7dda9306d03c79a30f5c56c44cf256e3de"
 [[package]]
 name = "async-trait"
 version = "0.1.89"
@@ -257,6 +407,12 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4c7f02d4ea65f2c1853089ffd8d2787bdbc63de2f0d29dedbcf8ccdfa0ccd4cf"
 [[package]]
 name = "base64"
 version = "0.21.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9d297deb1925b89f2ccc13d7635fa0714f12c87adce1c75356b39ca9b7178567"
 [[package]]
 name = "base64"
 version = "0.22.1"
@@ -308,6 +464,19 @@ dependencies = [
 "objc2",
 ]
 [[package]]
 name = "blocking"
 version = "1.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e83f8d02be6967315521be875afa792a316e28d57b5a2d401897e2a7921b7f21"
 dependencies = [
 "async-channel 2.5.0",
 "async-task",
 "futures-io",
 "futures-lite",
 "piper",
 ]
 [[package]]
 name = "build-target"
 version = "0.4.0"
@@ -352,6 +521,32 @@ version = "1.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1e748733b7cbc798e1434b6ac524f0c1ff2ab456fe201501e6497c8417a4fc33"
 [[package]]
 name = "cacache"
 version = "13.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5c5063741c7b2e260bbede781cf4679632dd90e2718e99f7715e46824b65670b"
 dependencies = [
 "async-std",
 "digest 0.10.7",
 "either",
 "futures",
 "hex",
 "libc",
 "memmap2",
 "miette",
 "reflink-copy",
 "serde",
 "serde_derive",
 "serde_json",
 "sha1",
 "sha2",
 "ssri",
 "tempfile",
 "thiserror 1.0.69",
 "walkdir",
 ]
 [[package]]
 name = "cast"
 version = "0.3.0"
@@ -475,11 +670,23 @@ dependencies = [
 "tracing-subscriber",
 ]
 [[package]]
 name = "chanora_cache"
 version = "0.2.0-beta.1"
 dependencies = [
 "cacache",
 "tempfile",
 "thiserror 2.0.18",
 "tokio",
 "tracing",
 ]
 [[package]]
 name = "chanora_core"
 version = "0.2.0-beta.1"
 dependencies = [
 "chanora_audio",
 "chanora_cache",
 "chanora_diagnostics",
 "chanora_prefetch",
 "chanora_protocol",
@@ -515,7 +722,7 @@ name = "chanora_protocol"
 version = "0.2.0-beta.1"
 dependencies = [
 "async-trait",
- "base64",
+ "base64 0.22.1",
 "chanora_resolver",
 "futures",
 "reqwest 0.13.4",
@@ -554,7 +761,7 @@ dependencies = [
 name = "chanora_storage"
 version = "0.2.0-beta.1"
 dependencies = [
- "base64",
+ "base64 0.22.1",
 "chacha20poly1305",
 "keyring",
 "rand 0.8.6",
@@ -1239,6 +1446,12 @@ dependencies = [
 "windows-sys 0.61.2",
 ]
 [[package]]
 name = "event-listener"
 version = "2.5.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0206175f82b8d6bf6652ff7d71a1e27fd2e4efde587fd368662814d6ec1d9ce0"
 [[package]]
 name = "event-listener"
 version = "5.4.1"
@@ -1256,7 +1469,7 @@ version = "0.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8be9f3dfaaffdae2972880079a491a1a8bb7cbed0b8dd7a347f668b4150a3b93"
 dependencies = [
- "event-listener",
+ "event-listener 5.4.1",
 "pin-project-lite",
 ]
@@ -1559,6 +1772,18 @@ dependencies = [
 "time",
 ]
 [[package]]
 name = "gloo-timers"
 version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bbb143cf96099802033e0d4f4963b19fd2e0b728bcf076cd9cf7f6634f092994"
 dependencies = [
 "futures-channel",
 "futures-core",
 "js-sys",
 "wasm-bindgen",
 ]
 [[package]]
 name = "group"
 version = "0.13.0"
@@ -1837,7 +2062,7 @@ version = "0.1.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "96547c2556ec9d12fb1578c4eaf448b04993e7fb79cbaad930a656880a6bdfa0"
 dependencies = [
- "base64",
+ "base64 0.22.1",
 "bytes",
 "futures-channel",
 "futures-util",
@@ -2142,6 +2367,15 @@ dependencies = [
 "zeroize",
 ]
 [[package]]
 name = "kv-log-macro"
 version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0de8b303297635ad57c9f5059fd9cee7a47f8e8daa09df0fcd07dd39fb22977f"
 dependencies = [
 "log",
 ]
 [[package]]
 name = "lazy_static"
 version = "1.5.0"
@@ -2226,6 +2460,9 @@ name = "log"
 version = "0.4.31"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "113b30b4cd05f7c06868fdb2854f66a7b9fece9a48425351cd532e810d74024f"
 dependencies = [
 "value-bag",
 ]
 [[package]]
 name = "lru-slab"
@@ -2274,6 +2511,15 @@ version = "2.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6b947ae49db0d222b1dbc6b113ce7248a3fc3a6ca21b696717bfc000ba4484d8"
 [[package]]
 name = "memmap2"
 version = "0.5.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "83faa42c0a078c393f6b29d5db232d8be22776a891f8f56e5284faee4a20b327"
 dependencies = [
 "libc",
 ]
 [[package]]
 name = "memoffset"
 version = "0.9.1"
@@ -2283,6 +2529,29 @@ dependencies = [
 "autocfg",
 ]
 [[package]]
 name = "miette"
 version = "5.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "59bb584eaeeab6bd0226ccf3509a69d7936d148cf3d036ad350abe35e8c6856e"
 dependencies = [
 "miette-derive",
 "once_cell",
 "thiserror 1.0.69",
 "unicode-width",
 ]
 [[package]]
 name = "miette-derive"
 version = "5.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "49e7bc1560b95a3c4a25d03de42fe76ca718ab92d1a22a55b9b4cf67b3ae635c"
 dependencies = [
 "proc-macro2",
 "quote",
 "syn",
 ]
 [[package]]
 name = "mime"
 version = "0.3.17"
@@ -2813,6 +3082,17 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
 [[package]]
 name = "piper"
 version = "0.2.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c835479a4443ded371d6c535cbfd8d31ad92c5d23ae9770a61bc155e4992a3c1"
 dependencies = [
 "atomic-waker",
 "fastrand",
 "futures-io",
 ]
 [[package]]
 name = "pkcs8"
 version = "0.10.2"
@@ -2857,6 +3137,20 @@ dependencies = [
 "plotters-backend",
 ]
 [[package]]
 name = "polling"
 version = "3.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5d0e4f59085d47d8241c88ead0f274e8a0cb551f3625263c05eb8dd897c34218"
 dependencies = [
 "cfg-if",
 "concurrent-queue",
 "hermit-abi",
 "pin-project-lite",
 "rustix",
 "windows-sys 0.61.2",
 ]
 [[package]]
 name = "poly1305"
 version = "0.8.0"
@@ -3183,6 +3477,18 @@ dependencies = [
 "syn",
 ]
 [[package]]
 name = "reflink-copy"
 version = "0.1.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "13362233b147e57674c37b802d216b7c5e3dcccbed8967c84f0d8d223868ae27"
 dependencies = [
 "cfg-if",
 "libc",
 "rustix",
 "windows",
 ]
 [[package]]
 name = "regex"
 version = "1.12.3"
@@ -3218,7 +3524,7 @@ version = "0.12.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "eddd3ca559203180a307f12d114c268abf583f59b03cb906fd0b3ff8646c1147"
 dependencies = [
- "base64",
+ "base64 0.22.1",
 "bytes",
 "futures-core",
 "http",
@@ -3256,7 +3562,7 @@ version = "0.13.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "219c5811de6525e5416c7d5d53bb656d3afdbc6c5af816e0802bcfa42dbdc1c3"
 dependencies = [
- "base64",
+ "base64 0.22.1",
 "bytes",
 "encoding_rs",
 "futures-core",
@@ -3672,6 +3978,17 @@ dependencies = [
 "digest 0.10.7",
 ]
 [[package]]
 name = "sha1"
 version = "0.10.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3bf829a2d51ab4a5ddf1352d8470c140cadc8301b2ae1789db023f01cedd6ba"
 dependencies = [
 "cfg-if",
 "cpufeatures 0.2.17",
 "digest 0.10.7",
 ]
 [[package]]
 name = "sha2"
 version = "0.10.9"
@@ -3851,6 +4168,23 @@ dependencies = [
 "der",
 ]
 [[package]]
 name = "ssri"
 version = "9.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "da7a2b3c2bc9693bcb40870c4e9b5bf0d79f9cb46273321bf855ec513e919082"
 dependencies = [
 "base64 0.21.7",
 "digest 0.10.7",
 "hex",
 "miette",
 "serde",
 "sha-1",
 "sha2",
 "thiserror 1.0.69",
 "xxhash-rust",
 ]
 [[package]]
 name = "stable_deref_trait"
 version = "1.2.1"
@@ -4349,7 +4683,7 @@ name = "ts-bookkeeping"
 version = "0.1.0"
 source = "git+https://github.com/ReSpeak/tsclientlib.git?rev=04aa2491#04aa24917abbf6a0c8442a79742d6d2d40ecf71e"
 dependencies = [
- "base64",
+ "base64 0.22.1",
 "heck",
 "itertools 0.14.0",
 "num-derive",
@@ -4370,7 +4704,7 @@ version = "0.2.0"
 source = "git+https://github.com/ReSpeak/tsclientlib.git?rev=04aa2491#04aa24917abbf6a0c8442a79742d6d2d40ecf71e"
 dependencies = [
 "audiopus",
- "base64",
+ "base64 0.22.1",
 "futures",
 "git-testament",
 "hickory-net",
@@ -4398,7 +4732,7 @@ version = "0.2.0"
 source = "git+https://github.com/ReSpeak/tsclientlib.git?rev=04aa2491#04aa24917abbf6a0c8442a79742d6d2d40ecf71e"
 dependencies = [
 "aes",
- "base64",
+ "base64 0.22.1",
 "curve25519-dalek-ng",
 "eax",
 "futures",
@@ -4427,7 +4761,7 @@ name = "tsproto-packets"
 version = "0.1.0"
 source = "git+https://github.com/ReSpeak/tsclientlib.git?rev=04aa2491#04aa24917abbf6a0c8442a79742d6d2d40ecf71e"
 dependencies = [
- "base64",
+ "base64 0.22.1",
 "bitflags 2.12.1",
 "num-derive",
 "num-traits",
@@ -4442,7 +4776,7 @@ name = "tsproto-structs"
 version = "0.2.0"
 source = "git+https://github.com/EdisonJwa/tsclientlib.git?branch=fix%2Fp256-short-coordinate-pad#8b7a3226c692319b714ea1d32fd5ded05911aa40"
 dependencies = [
- "base64",
+ "base64 0.22.1",
 "csv",
 "heck",
 "once_cell",
@@ -4455,7 +4789,7 @@ name = "tsproto-structs"
 version = "0.2.0"
 source = "git+https://github.com/ReSpeak/tsclientlib.git?rev=04aa2491#04aa24917abbf6a0c8442a79742d6d2d40ecf71e"
 dependencies = [
- "base64",
+ "base64 0.22.1",
 "csv",
 "heck",
 "once_cell",
@@ -4468,7 +4802,7 @@ name = "tsproto-types"
 version = "0.1.0"
 source = "git+https://github.com/EdisonJwa/tsclientlib.git?branch=fix%2Fp256-short-coordinate-pad#8b7a3226c692319b714ea1d32fd5ded05911aa40"
 dependencies = [
- "base64",
+ "base64 0.22.1",
 "bitflags 2.12.1",
 "curve25519-dalek-ng",
 "elliptic-curve",
@@ -4512,6 +4846,12 @@ version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 [[package]]
 name = "unicode-width"
 version = "0.1.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7dd6e30e90baa6f72411720665d41d89b9a3d039dc45b8faea1ddd07f617f6af"
 [[package]]
 name = "unicode-xid"
 version = "0.2.6"
@@ -4570,6 +4910,12 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ba73ea9cf16a25df0c8caa16c51acb937d5712a8429db78a3ee29d5dcacd3a65"
 [[package]]
 name = "value-bag"
 version = "1.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7ba6f5989077681266825251a52748b8c1d8a4ad098cc37e440103d0ea717fc0"
 [[package]]
 name = "vcpkg"
 version = "0.2.15"
@@ -5256,6 +5602,12 @@ version = "0.6.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1ffae5123b2d3fc086436f8834ae3ab053a283cfac8fe0a0b8eaae044768a4c4"
 [[package]]
 name = "xxhash-rust"
 version = "0.8.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fdd20c5420375476fbd4394763288da7eb0cc0b8c11deed431a91562af7335d3"
 [[package]]
 name = "yoke"
 version = "0.8.2"
@@ -5289,7 +5641,7 @@ dependencies = [
 "async-recursion",
 "async-trait",
 "enumflags2",
- "event-listener",
+ "event-listener 5.4.1",
 "futures-core",
 "futures-lite",
 "hex",
@@ -10,6 +10,7 @@
 #   crates/chanora_resolver/     — TeamSpeak address resolution
 #   crates/chanora_state/        — snapshot, deltas, reducers
 #   crates/chanora_audio/        — capture, DSP, Opus, jitter, mixer
 #   crates/chanora_cache/        — avatar/icon blob cache (cacache-backed)
 #   crates/chanora_storage/      — bookmarks, settings, identity refs
 #   crates/chanora_diagnostics/  — logs, redaction, export
 #   crates/chanora_prefetch — server-resolution prefetch cache/policy
@@ -30,6 +31,7 @@ members = [
    "crates/chanora_state",
    "crates/chanora_audio",
    "crates/chanora_storage",
    "crates/chanora_cache",
    "crates/chanora_diagnostics",
    "crates/chanora_prefetch",
    "crates/chanora_bridge",
@@ -93,7 +93,10 @@ String _kAppVersion = appSemverBaseline;
 Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await RustLib.init();
-  unawaited(wireStorage());
+  unawaited(() async {
    await wireStorage();
    await wireCache();
  }());
  unawaited(wireConnectivity());
  wireAudioLifecycle();
  await configureBundledVadModels();
@@ -15,15 +15,22 @@ typedef StorageDirectoryProvider = Future<Directory> Function();
 typedef StorageInitializer = Future<void> Function(String dir);
 Future<void>? _storageInitFuture;
 Future<void>? _cacheInitFuture;
 Future<void>? _vadBootstrapFuture;
 StorageDirectoryProvider _storageDirectoryProvider =
    getApplicationSupportDirectory;
 StorageDirectoryProvider _cacheDirectoryProvider = getApplicationCacheDirectory;
 StorageInitializer _storageInitializer = _defaultStorageInitializer;
 StorageInitializer _cacheInitializer = _defaultCacheInitializer;
 Future<void> _defaultStorageInitializer(String dir) {
  return rust.initStorage(dir: dir);
 }
 Future<void> _defaultCacheInitializer(String dir) {
  return rust.initCache(dir: dir);
 }
 Future<File> _copyBundledAssetToDocuments({
  required String assetPath,
  required String fileName,
@@ -121,16 +128,50 @@ Future<void> _wireStorageImpl() async {
  }
 }
 Future<void> wireCache() async {
  final existing = _cacheInitFuture;
  if (existing != null) {
    await existing;
    return;
  }
  final initFuture = _wireCacheImpl();
  _cacheInitFuture = initFuture;
  await initFuture;
 }
 Future<void> _wireCacheImpl() async {
  var initialized = false;
  try {
    final dir = await _cacheDirectoryProvider();
    await _cacheInitializer(dir.path);
    initialized = true;
  } catch (_) {
    // Best-effort; missing cache just means protocol-owned assets are
    // re-downloaded this session.
  } finally {
    if (!initialized) {
      _cacheInitFuture = null;
    }
  }
 }
@visibleForTesting
 void debugResetStorageBootstrap({
  StorageDirectoryProvider? storageDirectoryProvider,
  StorageDirectoryProvider? cacheDirectoryProvider,
  StorageInitializer? storageInitializer,
  StorageInitializer? cacheInitializer,
 }) {
  _storageInitFuture = null;
  _cacheInitFuture = null;
  _vadBootstrapFuture = null;
  _storageDirectoryProvider =
      storageDirectoryProvider ?? getApplicationSupportDirectory;
  _cacheDirectoryProvider =
      cacheDirectoryProvider ?? getApplicationCacheDirectory;
  _storageInitializer = storageInitializer ?? _defaultStorageInitializer;
  _cacheInitializer = cacheInitializer ?? _defaultCacheInitializer;
 }
 rust.BridgeNetworkState _mapConnectivity(List<ConnectivityResult> results) {
@@ -226,6 +226,41 @@ String exportDiagnostics() => RustLib.instance.api.crateApiExportDiagnostics();
 Future<void> initStorage({required String dir}) =>
    RustLib.instance.api.crateApiInitStorage(dir: dir);
 /// Wire the blob cache to a platform-private cache directory.
 Future<void> initCache({required String dir}) {
  final api = RustLib.instance.api as dynamic;
  try {
    return api.crateApiInitCache(dir: dir) as Future<void>;
  } on NoSuchMethodError {
    return Future.value();
  }
 }
 /// Return an avatar from cache when present; otherwise download it.
 Future<List<int>?> downloadAvatar({
  required String avatarHash,
  required String clientUid,
 }) {
  final api = RustLib.instance.api as dynamic;
  try {
    return api.crateApiDownloadAvatar(
      avatarHash: avatarHash,
      clientUid: clientUid,
    ) as Future<List<int>?>;
  } on NoSuchMethodError {
    return Future.value();
  }
 }
 Future<List<int>?> downloadIcon({required BigInt iconId}) {
  final api = RustLib.instance.api as dynamic;
  try {
    return api.crateApiDownloadIcon(iconId: iconId) as Future<List<int>?>;
  } on NoSuchMethodError {
    return Future.value();
  }
 }
 /// List persisted bookmarks.
 Future<List<BridgeBookmark>> listBookmarks() =>
    RustLib.instance.api.crateApiListBookmarks();
@@ -10,6 +10,7 @@ repository.workspace = true
 publish.workspace = true
 [dependencies]
 chanora_cache = { path = "../../crates/chanora_cache" }
 chanora_protocol = { path = "../../crates/chanora_protocol" }
 chanora_state    = { path = "../../crates/chanora_state" }
 chanora_audio    = { path = "../../crates/chanora_audio" }
@@ -0,0 +1,344 @@
 use std::collections::HashMap;
 use std::sync::Arc;
 use std::time::{Duration, Instant};
 use chanora_cache::{BlobCache, BlobCacheError, PREFIX_AVATAR, PREFIX_ICON};
 use chanora_protocol::{ProtocolClient, ProtocolError};
 use tokio::sync::{Mutex, Semaphore, oneshot};
 use tracing::warn;
 const MAX_CONCURRENT_DOWNLOADS: usize = 2;
 const NEGATIVE_CACHE_TTL: Duration = Duration::from_secs(5 * 60);
 type InFlightWaiters = Vec<oneshot::Sender<Result<Option<Vec<u8>>, FileTransferError>>>;
 /// Errors raised while resolving protocol-owned file assets.
 #[derive(Debug, thiserror::Error)]
 pub enum FileTransferError {
    /// No live protocol client is available for a download.
    #[error("not connected")]
    NotConnected,
    /// The protocol layer failed while downloading the asset.
    #[error("protocol error: {0}")]
    Protocol(#[from] ProtocolError),
    /// The blob cache failed while reading or writing the asset.
    #[error("cache error: {0}")]
    Cache(#[from] BlobCacheError),
 }
 impl Clone for FileTransferError {
    fn clone(&self) -> Self {
        match self {
            Self::NotConnected => Self::NotConnected,
            Self::Protocol(error) => Self::Protocol(clone_protocol_error(error)),
            Self::Cache(error) => Self::Cache(clone_blob_cache_error(error)),
        }
    }
 }
 pub struct FileTransferService {
    cache: BlobCache,
    protocol: Arc<Mutex<Option<ProtocolClient>>>,
    semaphore: Arc<Semaphore>,
    in_flight: Arc<Mutex<HashMap<String, InFlightWaiters>>>,
    negative_cache: Arc<Mutex<HashMap<String, Instant>>>,
 }
 impl FileTransferService {
    pub fn new(cache: BlobCache, protocol: Arc<Mutex<Option<ProtocolClient>>>) -> Self {
        Self {
            cache,
            protocol,
            semaphore: Arc::new(Semaphore::new(MAX_CONCURRENT_DOWNLOADS)),
            in_flight: Arc::new(Mutex::new(HashMap::new())),
            negative_cache: Arc::new(Mutex::new(HashMap::new())),
        }
    }
    pub async fn set_protocol(&self, client: Option<ProtocolClient>) {
        *self.protocol.lock().await = client;
    }
    pub async fn get_avatar(
        &self,
        avatar_hash: &str,
        client_uid: &str,
    ) -> Result<Option<Vec<u8>>, FileTransferError> {
        if let Some(bytes) = self.cache.get(PREFIX_AVATAR, avatar_hash).await? {
            return Ok(Some(bytes));
        }
        if self.is_negative_cache_hit(avatar_hash).await {
            return Ok(None);
        }
        let rx = {
            let mut in_flight = self.in_flight.lock().await;
            if let Some(waiters) = in_flight.get_mut(avatar_hash) {
                let (tx, rx) = oneshot::channel();
                waiters.push(tx);
                Some(rx)
            } else {
                in_flight.insert(avatar_hash.to_string(), Vec::new());
                None
            }
        };
        if let Some(rx) = rx {
            return rx.await.unwrap_or_else(|_| {
                Err(FileTransferError::Protocol(ProtocolError::Lost(
                    "coalesced avatar download waiter dropped".to_string(),
                )))
            });
        }
        let _permit = self
            .semaphore
            .acquire()
            .await
            .expect("file transfer semaphore should stay open");
        let result = self.do_download_avatar(avatar_hash, client_uid).await;
        self.finish_in_flight(avatar_hash, &result).await;
        result
    }
    pub async fn get_icon(&self, icon_id: u64) -> Result<Option<Vec<u8>>, FileTransferError> {
        let icon_key = icon_id.to_string();
        let negative_key = format!("ic_{icon_id}");
        let in_flight_key = format!("icon_{icon_id}");
        if let Some(bytes) = self.cache.get(PREFIX_ICON, &icon_key).await? {
            return Ok(Some(bytes));
        }
        if self.is_negative_cache_hit(&negative_key).await {
            return Ok(None);
        }
        let rx = {
            let mut in_flight = self.in_flight.lock().await;
            if let Some(waiters) = in_flight.get_mut(&in_flight_key) {
                let (tx, rx) = oneshot::channel();
                waiters.push(tx);
                Some(rx)
            } else {
                in_flight.insert(in_flight_key.clone(), Vec::new());
                None
            }
        };
        if let Some(rx) = rx {
            return rx.await.unwrap_or_else(|_| {
                Err(FileTransferError::Protocol(ProtocolError::Lost(
                    "coalesced icon download waiter dropped".to_string(),
                )))
            });
        }
        let _permit = self
            .semaphore
            .acquire()
            .await
            .expect("file transfer semaphore should stay open");
        let result = self.do_download_icon(icon_id).await;
        self.finish_in_flight(&in_flight_key, &result).await;
        result
    }
    pub async fn clear_cache(&self) -> Result<(), FileTransferError> {
        self.cache.clear().await?;
        self.negative_cache.lock().await.clear();
        Ok(())
    }
    pub async fn cache_size(&self) -> Result<u64, FileTransferError> {
        Ok(self.cache.total_size().await?)
    }
    async fn do_download_avatar(
        &self,
        avatar_hash: &str,
        client_uid: &str,
    ) -> Result<Option<Vec<u8>>, FileTransferError> {
        if let Some(bytes) = self.cache.get(PREFIX_AVATAR, avatar_hash).await? {
            return Ok(Some(bytes));
        }
        if self.is_negative_cache_hit(avatar_hash).await {
            return Ok(None);
        }
        let protocol = self.protocol.lock().await;
        let client = protocol.as_ref().ok_or(FileTransferError::NotConnected)?;
        match client.download_avatar(client_uid).await {
            Ok(bytes) => {
                self.cache.put(PREFIX_AVATAR, avatar_hash, &bytes).await?;
                self.negative_cache.lock().await.remove(avatar_hash);
                Ok(Some(bytes))
            }
            Err(ProtocolError::ServerRejected { .. }) => {
                self.negative_cache
                    .lock()
                    .await
                    .insert(avatar_hash.to_string(), Instant::now() + NEGATIVE_CACHE_TTL);
                Ok(None)
            }
            Err(error) => Err(FileTransferError::Protocol(error)),
        }
    }
    async fn do_download_icon(&self, icon_id: u64) -> Result<Option<Vec<u8>>, FileTransferError> {
        let icon_key = icon_id.to_string();
        let negative_key = format!("ic_{icon_id}");
        if let Some(bytes) = self.cache.get(PREFIX_ICON, &icon_key).await? {
            return Ok(Some(bytes));
        }
        if self.is_negative_cache_hit(&negative_key).await {
            return Ok(None);
        }
        let protocol = self.protocol.lock().await;
        let client = protocol.as_ref().ok_or(FileTransferError::NotConnected)?;
        match client.download_icon(icon_id).await {
            Ok(bytes) => {
                self.cache.put(PREFIX_ICON, &icon_key, &bytes).await?;
                self.negative_cache.lock().await.remove(&negative_key);
                Ok(Some(bytes))
            }
            Err(ProtocolError::ServerRejected { .. }) => {
                self.negative_cache
                    .lock()
                    .await
                    .insert(negative_key, Instant::now() + NEGATIVE_CACHE_TTL);
                Ok(None)
            }
            Err(error) => Err(FileTransferError::Protocol(error)),
        }
    }
    async fn finish_in_flight(
        &self,
        avatar_hash: &str,
        result: &Result<Option<Vec<u8>>, FileTransferError>,
    ) {
        let waiters = self.in_flight.lock().await.remove(avatar_hash).unwrap_or_default();
        for waiter in waiters {
            if waiter.send(result.clone()).is_err() {
                warn!(target: "chanora_core", avatar_hash, "avatar download waiter dropped");
            }
        }
    }
    async fn is_negative_cache_hit(&self, avatar_hash: &str) -> bool {
        let now = Instant::now();
        let mut negative_cache = self.negative_cache.lock().await;
        match negative_cache.get(avatar_hash).copied() {
            Some(expires_at) if expires_at > now => true,
            Some(_) => {
                negative_cache.remove(avatar_hash);
                false
            }
            None => false,
        }
    }
 }
 fn clone_protocol_error(error: &ProtocolError) -> ProtocolError {
    match error {
        ProtocolError::Invalid(message) => ProtocolError::Invalid(message.clone()),
        ProtocolError::DnsFailed { host, reason } => ProtocolError::DnsFailed {
            host: host.clone(),
            reason: reason.clone(),
        },
        ProtocolError::Connect(message) => ProtocolError::Connect(message.clone()),
        ProtocolError::DisconnectedEarly(message) => {
            ProtocolError::DisconnectedEarly(message.clone())
        }
        ProtocolError::Lost(message) => ProtocolError::Lost(message.clone()),
        ProtocolError::Identity(message) => ProtocolError::Identity(message.clone()),
        ProtocolError::Timeout => ProtocolError::Timeout,
        ProtocolError::ServerRejected { code, message } => ProtocolError::ServerRejected {
            code: *code,
            message: message.clone(),
        },
        ProtocolError::Backend(message) => ProtocolError::Backend(message.clone()),
        ProtocolError::FileTransfer(message) => ProtocolError::FileTransfer(message.clone()),
    }
 }
 fn clone_blob_cache_error(error: &BlobCacheError) -> BlobCacheError {
    match error {
        BlobCacheError::Io(message) => BlobCacheError::Io(message.clone()),
        BlobCacheError::InvalidKey(message) => BlobCacheError::InvalidKey(message.clone()),
    }
 }
 #[cfg(test)]
 mod tests {
    use super::*;
    fn test_cache_dir(name: &str) -> std::path::PathBuf {
        let mut path = std::env::temp_dir();
        let nanos = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap()
            .as_nanos();
        path.push(format!("chanora-core-file-transfer-{name}-{nanos}"));
        path
    }
    #[tokio::test]
    async fn returns_cached_avatar_without_connection() {
        let cache_dir = test_cache_dir("cache-hit");
        let cache = BlobCache::new(&cache_dir, 1024).unwrap();
        cache.put(PREFIX_AVATAR, "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6", b"avatar")
            .await
            .unwrap();
        let service = FileTransferService::new(cache, Arc::new(Mutex::new(None)));
        let avatar = service
            .get_avatar("a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6", "client")
            .await
            .unwrap();
        assert_eq!(avatar, Some(b"avatar".to_vec()));
        let _ = std::fs::remove_dir_all(cache_dir);
    }
    #[tokio::test]
    async fn negative_cache_short_circuits_not_connected() {
        let cache_dir = test_cache_dir("negative-cache");
        let cache = BlobCache::new(&cache_dir, 1024).unwrap();
        let service = FileTransferService::new(cache, Arc::new(Mutex::new(None)));
        service
            .negative_cache
            .lock()
            .await
            .insert("a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6".to_string(), Instant::now() + NEGATIVE_CACHE_TTL);
        let avatar = service
            .get_avatar("a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6", "client")
            .await
            .unwrap();
        assert_eq!(avatar, None);
        let _ = std::fs::remove_dir_all(cache_dir);
    }
    #[tokio::test]
    async fn returns_cached_icon_without_connection() {
        let cache_dir = test_cache_dir("icon-cache-hit");
        let cache = BlobCache::new(&cache_dir, 1024).unwrap();
        cache.put(PREFIX_ICON, "12345", b"icon").await.unwrap();
        let service = FileTransferService::new(cache, Arc::new(Mutex::new(None)));
        let icon = service.get_icon(12345).await.unwrap();
        assert_eq!(icon, Some(b"icon".to_vec()));
        let _ = std::fs::remove_dir_all(cache_dir);
    }
 }
@@ -53,6 +53,7 @@ use chanora_state::channel_join::{
 };
 mod events;
 mod file_transfer;
 mod network_diagnostics;
 pub mod ptt;
@@ -75,6 +76,7 @@ pub use events::{
    NetworkState, PersistedPttBinding, PttDescriptorSnapshot, SessionEvent, VoiceJoinErrorCode,
    VoiceJoinSyncState,
 };
 pub use file_transfer::FileTransferError;
 use network_diagnostics::NetworkDiagnostics;
 /// Errors that can arise during top-level orchestration.
@@ -92,6 +94,12 @@ pub enum CoreError {
    /// Storage error.
    #[error("storage: {0}")]
    Storage(#[from] chanora_storage::StorageError),
    /// Blob-cache failure.
    #[error("cache: {0}")]
    Cache(#[from] chanora_cache::BlobCacheError),
    /// File-transfer failure.
    #[error("file transfer: {0}")]
    FileTransfer(#[from] FileTransferError),
    /// Diagnostics error.
    #[error("diagnostics: {0}")]
    Diagnostics(#[from] chanora_diagnostics::DiagnosticsError),
@@ -130,7 +138,6 @@ struct SupervisorInner {
 }
 struct ConnectedState {
    protocol: chanora_protocol::ProtocolClient,
    audio: Option<chanora_audio::AudioEngine>,
    /// Active PTT controller (SDD-088). Owns the platform input
    /// backend, the active binding, and the capability watch
@@ -197,6 +204,8 @@ pub struct ChanoraSession {
    /// extension). Lives alongside the identity file. Wired by
    /// [`Self::init_storage`].
    bookmark_store: Arc<Mutex<Option<BookmarkRepository>>>,
    protocol: Arc<Mutex<Option<chanora_protocol::ProtocolClient>>>,
    file_transfer: Arc<Mutex<Option<Arc<file_transfer::FileTransferService>>>>,
    /// Invisible server-address prefetch cache. Warmed by Flutter typing
    /// but validated by Rust before Connect can reuse it.
    server_prefetch: ServerPrefetcher,
@@ -252,6 +261,8 @@ impl ChanoraSession {
            network_tx,
            identity_store: Arc::new(Mutex::new(None)),
            bookmark_store: Arc::new(Mutex::new(None)),
            protocol: Arc::new(Mutex::new(None)),
            file_transfer: Arc::new(Mutex::new(None)),
            server_prefetch: ServerPrefetcher::new(),
            voice_selector: selector,
            release_tail,
@@ -273,6 +284,17 @@ impl ChanoraSession {
        ConnectionEpoch(epoch)
    }
    async fn store_protocol(&self, client: Option<chanora_protocol::ProtocolClient>) {
        // Always update the shared Arc. The FileTransferService holds
        // the same Arc, so it sees the new client automatically — no
        // separate set_protocol call needed.
        *self.protocol.lock().await = client;
    }
    async fn take_protocol(&self) -> Option<chanora_protocol::ProtocolClient> {
        self.protocol.lock().await.take()
    }
    /// Wire a directory-backed identity store. Called by the bridge
    /// during `bridge_init` once Flutter has resolved the platform
    /// app-private storage directory. Subsequent [`Self::connect`]
@@ -337,6 +359,65 @@ impl ChanoraSession {
        Ok(())
    }
    /// Configure the blob cache root.
    pub async fn init_cache(&self, dir: &str) -> Result<(), CoreError> {
        let cache = chanora_cache::BlobCache::new(dir, 100 * 1024 * 1024)?;
        cache.evict().await?;
        let service = Arc::new(file_transfer::FileTransferService::new(
            cache,
            self.protocol.clone(),
        ));
        let mut guard = self.file_transfer.lock().await;
        *guard = Some(service);
        Ok(())
    }
    /// Resolve avatar bytes.
    pub async fn get_avatar(
        &self,
        avatar_hash: &str,
        client_uid: &str,
    ) -> Result<Option<Vec<u8>>, CoreError> {
        let service = { self.file_transfer.lock().await.clone() };
        if let Some(service) = service {
            return Ok(service.get_avatar(avatar_hash, client_uid).await?);
        }
        let protocol = self.protocol.lock().await;
        let client = protocol.as_ref().ok_or(CoreError::NotConnected)?;
        Ok(Some(client.download_avatar(client_uid).await?))
    }
    /// Resolve icon bytes.
    pub async fn get_icon(&self, icon_id: u64) -> Result<Option<Vec<u8>>, CoreError> {
        let service = { self.file_transfer.lock().await.clone() };
        if let Some(service) = service {
            return Ok(service.get_icon(icon_id).await?);
        }
        let protocol = self.protocol.lock().await;
        let client = protocol.as_ref().ok_or(CoreError::NotConnected)?;
        Ok(Some(client.download_icon(icon_id).await?))
    }
    /// Purge cached protocol-owned assets.
    pub async fn clear_cache(&self) -> Result<(), CoreError> {
        let service = { self.file_transfer.lock().await.clone() };
        if let Some(service) = service {
            service.clear_cache().await?;
        }
        Ok(())
    }
    /// Report the configured blob-cache size.
    pub async fn cache_size(&self) -> Result<u64, CoreError> {
        let service = { self.file_transfer.lock().await.clone() };
        match service {
            Some(service) => Ok(service.cache_size().await?),
            None => Ok(0),
        }
    }
    /// List persisted bookmarks. Returns an empty list if the store
    /// has not been wired or has no entries.
    pub async fn list_bookmarks(&self) -> Result<Vec<Bookmark>, CoreError> {
@@ -514,6 +595,7 @@ impl ChanoraSession {
        let supervisor = tokio::spawn(supervisor_loop(SupervisorContext {
            state_arc: self.inner.clone(),
            protocol: self.protocol.clone(),
            events_tx: self.events_tx.clone(),
            initial_cfg: cfg.clone(),
            initial_lost_rx: lost_rx,
@@ -568,9 +650,9 @@ impl ChanoraSession {
        }
        spawn_event_forwarders(&client, &self.events_tx);
        self.store_protocol(Some(client)).await;
        *guard = Some(ConnectedState {
            protocol: client,
            audio: None,
            ptt_controller: None,
            cancel_tx: Some(cancel_tx),
@@ -631,9 +713,13 @@ impl ChanoraSession {
    /// Return a fresh snapshot of the current server state.
    pub async fn snapshot(&self) -> Result<ServerSnapshot, CoreError> {
        let snap = {
            let protocol = self.protocol.lock().await;
            let client = protocol.as_ref().ok_or(CoreError::NotConnected)?;
            client.snapshot().await?
        };
        let mut guard = self.inner.lock().await;
        let state = guard.as_mut().ok_or(CoreError::NotConnected)?;
        let snap = state.protocol.snapshot().await?;
        let current_channel = self
            .find_own_in(&snap)
            .await
@@ -661,9 +747,9 @@ impl ChanoraSession {
    /// Fetch richer profile and live connection details for one online client.
    pub async fn client_profile(&self, client_id: u64) -> Result<ClientProfile, CoreError> {
-        let guard = self.inner.lock().await;
+        let protocol = self.protocol.lock().await;
-        let state = guard.as_ref().ok_or(CoreError::NotConnected)?;
+        let client = protocol.as_ref().ok_or(CoreError::NotConnected)?;
-        Ok(state.protocol.client_profile(client_id).await?)
+        Ok(client.client_profile(client_id).await?)
    }
    /// True if a connection is currently active.
@@ -680,9 +766,9 @@ impl ChanoraSession {
        if !should_dispatch_text_message(&message, &target) {
            return Ok(());
        }
-        let guard = self.inner.lock().await;
+        let protocol = self.protocol.lock().await;
-        let state = guard.as_ref().ok_or(CoreError::NotConnected)?;
+        let client = protocol.as_ref().ok_or(CoreError::NotConnected)?;
-        state.protocol.send_text_message(message, target).await?;
+        client.send_text_message(message, target).await?;
        Ok(())
    }
@@ -741,11 +827,16 @@ impl ChanoraSession {
        // session permanently unable to restart audio without a
        // reconnect (the user saw "voice_in already taken" on the
        // second channel switch).
-        let voice_out = state.protocol.voice_out();
+        let (voice_out, voice_in) = {
-        let voice_in = state
+            let protocol = self.protocol.lock().await;
-            .protocol
+            let client = protocol.as_ref().ok_or(CoreError::NotConnected)?;
            (
                client.voice_out(),
                client
                    .take_voice_in()
-            .ok_or(CoreError::Invariant("voice_in already taken"))?;
+                    .ok_or(CoreError::Invariant("voice_in already taken"))?,
            )
        };
        let gate = AudioTransmitGate::new(cfg.ptt_initial);
        cfg.voice_activity_selector = Some(self.voice_selector.clone());
        let new_engine = match chanora_audio::AudioEngine::start_with_gate(
@@ -976,10 +1067,11 @@ impl ChanoraSession {
        let password_to_send = requested_password
            .clone()
            .or_else(|| state.channel_passwords.get(&channel_id).cloned());
-        state
+        {
-            .protocol
+            let protocol = self.protocol.lock().await;
-            .move_to_channel(channel_id, password_to_send)
+            let client = protocol.as_ref().ok_or(CoreError::NotConnected)?;
-            .await?;
+            client.move_to_channel(channel_id, password_to_send).await?;
        }
        if let Some(pw) = requested_password {
            state.channel_passwords.insert(channel_id, pw);
        }
@@ -1004,7 +1096,11 @@ impl ChanoraSession {
        if let Some(muted) = output {
            state.local_output_muted = muted;
        }
-        state.protocol.set_muted(input, output).await?;
+        {
            let protocol = self.protocol.lock().await;
            let client = protocol.as_ref().ok_or(CoreError::NotConnected)?;
            client.set_muted(input, output).await?;
        }
        if let Some(muted) = output {
            if let Some(audio) = state.audio.as_ref() {
                audio.set_output_muted(muted);
@@ -1327,11 +1423,12 @@ impl ChanoraSession {
        let password_to_send = requested_password
            .clone()
            .or_else(|| state.channel_passwords.get(&channel_id).cloned());
-        if let Err(e) = state
+        let move_result = {
-            .protocol
+            let protocol = self.protocol.lock().await;
-            .queue_move_to_channel(channel_id, password_to_send)
+            let client = protocol.as_ref().ok_or(CoreError::NotConnected)?;
-            .await
+            client.queue_move_to_channel(channel_id, password_to_send).await
-        {
+        };
        if let Err(e) = move_result {
            // TS3 error 0x0302 = `channel_already_in`: we're already
            // in the target channel, so this is a no-op success.
            // Rolling `in_channel` back to false would break PTT
@@ -1593,7 +1690,9 @@ impl ChanoraSession {
                audio.stop();
                let _ = self.events_tx.send(SessionEvent::AudioStopped);
            }
-            state.protocol.disconnect().await;
+            if let Some(protocol) = self.take_protocol().await {
                protocol.disconnect().await;
            }
            // Wait for the supervisor to wind down so we don't race
            // a redial against the explicit disconnect.
            if let Some(handle) = state.supervisor.take() {
@@ -1655,6 +1754,7 @@ async fn await_supervisor_shutdown(mut handle: JoinHandle<()>, timeout_duration:
 struct SupervisorContext {
    state_arc: Arc<Mutex<Option<ConnectedState>>>,
    protocol: Arc<Mutex<Option<chanora_protocol::ProtocolClient>>>,
    events_tx: broadcast::Sender<SessionEvent>,
    initial_cfg: ConnectConfig,
    initial_lost_rx: oneshot::Receiver<chanora_protocol::DisconnectReason>,
@@ -1789,6 +1889,7 @@ fn spawn_event_forwarders(
 async fn supervisor_loop(ctx: SupervisorContext) {
    let SupervisorContext {
        state_arc,
        protocol,
        events_tx,
        initial_cfg,
        initial_lost_rx,
@@ -2058,20 +2159,21 @@ async fn supervisor_loop(ctx: SupervisorContext) {
                            // Reattach into the session state.
                            let restart_audio = {
                                let guard = state_arc.lock().await;
                                if guard.is_none() {
                                    // Session was disposed mid-reconnect.
                                    return;
                                }
                                drop(guard);
                                let old = protocol.lock().await.replace(new_client);
                                drop(old);
                                let mut guard = state_arc.lock().await;
                                let state = match guard.as_mut() {
                                    Some(s) => s,
                                    None => {
                                        // Session was disposed mid-reconnect.
                                        return;
                                    }
                                };
                                // Replace the dead protocol client with the new one.
                                // The old client's background task either already
                                // exited (loss notifier fired) or will exit when
                                // its request channel drops (watchdog path).
                                let old = std::mem::replace(&mut state.protocol, new_client);
                                drop(old);
                                let _ = channel_join::reduce(
                                    &mut state.join_state,
@@ -2101,9 +2203,9 @@ async fn supervisor_loop(ctx: SupervisorContext) {
                            });
                            {
-                                let guard = state_arc.lock().await;
+                                let protocol = protocol.lock().await;
-                                if let Some(state) = guard.as_ref() {
+                                if let Some(client) = protocol.as_ref() {
-                                    spawn_event_forwarders(&state.protocol, &events_tx);
+                                    spawn_event_forwarders(client, &events_tx);
                                }
                            }
@@ -2115,8 +2217,15 @@ async fn supervisor_loop(ctx: SupervisorContext) {
                                };
                                let mut guard = state_arc.lock().await;
                                if let Some(state) = guard.as_mut() {
-                                    let voice_out = state.protocol.voice_out();
+                                    let (voice_out, voice_in) = {
-                                    if let Some(voice_in) = state.protocol.take_voice_in() {
+                                        let protocol = protocol.lock().await;
                                        let client = match protocol.as_ref() {
                                            Some(client) => client,
                                            None => return,
                                        };
                                        (client.voice_out(), client.take_voice_in())
                                    };
                                    if let Some(voice_in) = voice_in {
                                        let gate = chanora_audio::AudioTransmitGate::new(
                                            audio_cfg.ptt_initial,
                                        );
@@ -0,0 +1,50 @@
 use std::env;
 use std::path::PathBuf;
 use std::process;
 use std::time::{SystemTime, UNIX_EPOCH};
 #[tokio::test]
 async fn get_avatar_returns_cached_bytes_without_connection() {
    let tmp = mktemp("chanora_core_avatar_cache_test");
    let session = chanora_core::ChanoraSession::new();
    session.init_cache(tmp.to_str().unwrap()).await.unwrap();
    let cache = chanora_cache::BlobCache::new(&tmp, 100 * 1024 * 1024).unwrap();
    let hash = "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6";
    cache
        .put(chanora_cache::PREFIX_AVATAR, hash, b"avatar-bytes")
        .await
        .unwrap();
    let bytes = session
        .get_avatar(hash, "client-uid")
        .await
        .unwrap()
        .unwrap();
    assert_eq!(bytes, b"avatar-bytes");
    let _ = std::fs::remove_dir_all(&tmp);
 }
 #[tokio::test]
 async fn get_avatar_without_cache_or_connection_returns_not_connected() {
    let session = chanora_core::ChanoraSession::new();
    let err = session
        .get_avatar("a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6", "client-uid")
        .await
        .unwrap_err();
    assert!(matches!(err, chanora_core::CoreError::NotConnected));
 }
 fn mktemp(label: &str) -> PathBuf {
    let nanos = SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .unwrap()
        .as_nanos();
    let p = env::temp_dir()
        .join(label)
        .join(format!("{}-{nanos}", process::id()));
    std::fs::create_dir_all(&p).unwrap();
    p
 }
@@ -1465,6 +1465,54 @@ pub async fn init_storage(dir: String) -> Result<(), BridgeError> {
    Ok(())
 }
 /// Configure the bridge blob cache root.
 pub async fn init_cache(dir: String) -> Result<(), BridgeError> {
    runtime()
        .spawn(async move { session().init_cache(&dir).await })
        .await
        .map_err(|e| task_join_error("init_cache", e))??;
    Ok(())
 }
 /// Resolve avatar bytes through the bridge.
 pub async fn download_avatar(
    avatar_hash: String,
    client_uid: String,
 ) -> Result<Option<Vec<u8>>, BridgeError> {
    runtime()
        .spawn(async move { session().get_avatar(&avatar_hash, &client_uid).await })
        .await
        .map_err(|e| task_join_error("download_avatar", e))?
        .map_err(BridgeError::from)
 }
 /// Resolve icon bytes through the bridge.
 pub async fn download_icon(icon_id: u64) -> Result<Option<Vec<u8>>, BridgeError> {
    runtime()
        .spawn(async move { session().get_icon(icon_id).await })
        .await
        .map_err(|e| task_join_error("download_icon", e))?
        .map_err(BridgeError::from)
 }
 /// Purge cached protocol-owned assets.
 pub async fn clear_file_cache() -> Result<(), BridgeError> {
    runtime()
        .spawn(async move { session().clear_cache().await })
        .await
        .map_err(|e| task_join_error("clear_file_cache", e))??;
    Ok(())
 }
 /// Report the configured file-cache size.
 pub async fn file_cache_size() -> Result<u64, BridgeError> {
    runtime()
        .spawn(async move { session().cache_size().await })
        .await
        .map_err(|e| task_join_error("file_cache_size", e))?
        .map_err(BridgeError::from)
 }
 /// Bookmark DTO mirroring [`chanora_core::Bookmark`].
 #[derive(Debug, Clone)]
 pub struct BridgeBookmark {
@@ -110,9 +110,13 @@ impl From<chanora_core::CoreError> for BridgeError {
                code,
                message,
            }) => BridgeError::ServerRejected { code, message },
            chanora_core::CoreError::Protocol(chanora_core::ProtocolError::FileTransfer(p)) => {
                BridgeError::Connection(format!("file transfer: {p}"))
            }
            chanora_core::CoreError::Protocol(p) => BridgeError::Connection(format!("{p}")),
            chanora_core::CoreError::Audio(a) => BridgeError::Connection(format!("audio: {a}")),
            chanora_core::CoreError::Storage(s) => BridgeError::Connection(format!("storage: {s}")),
            chanora_core::CoreError::Cache(c) => BridgeError::Connection(format!("cache: {c}")),
            other => BridgeError::Unmapped(format!("{other}")),
        }
    }
@@ -0,0 +1,20 @@
 [package]
 name = "chanora_cache"
 description = "Chanora disposable content-addressed blob cache for avatars and icons"
 version.workspace = true
 edition.workspace = true
 rust-version.workspace = true
 authors.workspace = true
 license.workspace = true
 repository.workspace = true
 publish.workspace = true
 [dependencies]
 cacache = "13"
 thiserror.workspace = true
 tokio = { version = "1", features = ["fs", "rt"] }
 tracing.workspace = true
 [dev-dependencies]
 tempfile = "3"
 tokio = { version = "1", features = ["rt", "macros", "time"] }
@@ -0,0 +1,359 @@
 //! Disposable content-addressed blob cache for avatar and icon files.
 //!
 //! Wraps [`cacache`] for production-tested crash safety and integrity
 //! verification. The on-disk layout is managed by cacache (content-v2,
 //! index-v2). Chanora maps protocol keys (`av_<md5>`, `ic_<crc32>`) to
 //! cacache string keys.
 //!
 //! This crate is intentionally separate from `chanora_storage`:
 //! storage owns persistent identity/bookmark data; cache owns
 //! reconstructible, disposable blob data with different durability
 //! and backup semantics.
 #![forbid(unsafe_code)]
 #![warn(missing_docs)]
 use std::path::{Path, PathBuf};
 /// Errors raised by the blob cache.
 #[derive(Debug, thiserror::Error)]
 pub enum BlobCacheError {
    /// Filesystem I/O error.
    #[error("io: {0}")]
    Io(String),
    /// Key validation error.
    #[error("invalid key: {0}")]
    InvalidKey(String),
 }
 /// Content-addressed blob cache backed by cacache.
 pub struct BlobCache {
    cache_dir: PathBuf,
    /// Maximum total cache size in bytes. 0 = no limit.
    max_bytes: u64,
 }
 /// Avatar blob prefix.
 pub const PREFIX_AVATAR: &str = "av_";
 /// Icon blob prefix.
 pub const PREFIX_ICON: &str = "ic_";
 impl BlobCache {
    /// Create or open a [`BlobCache`] rooted at `cache_dir/chanora/`.
    ///
    /// Creates the cacache directory. `max_bytes` sets the eviction
    /// threshold; 0 means no automatic eviction.
    pub fn new(cache_dir: impl AsRef<Path>, max_bytes: u64) -> Result<Self, BlobCacheError> {
        let cache_dir = cache_dir.as_ref().join("chanora").join("blobs");
        // cacache creates the directory on first write, but we create
        // it eagerly so total_size() works before any writes.
        std::fs::create_dir_all(&cache_dir)
            .map_err(|e| BlobCacheError::Io(format!("mkdir cache: {e}")))?;
        Ok(Self {
            cache_dir,
            max_bytes,
        })
    }
    /// Store a blob. `prefix` is [`PREFIX_AVATAR`] or [`PREFIX_ICON`].
    /// `key` is the content hash (MD5 hex for avatars, unsigned
    /// decimal CRC32 for icons).
    ///
    /// Cacache handles dedup and integrity internally.
    pub async fn put(
        &self,
        prefix: &str,
        key: &str,
        data: &[u8],
    ) -> Result<(), BlobCacheError> {
        validate_key(prefix, key)?;
        let cache_key = format!("{prefix}{key}");
        cacache::write(&self.cache_dir, &cache_key, data)
            .await
            .map_err(|e| BlobCacheError::Io(format!("cacache write: {e}")))?;
        Ok(())
    }
    /// Read a blob. Returns `None` if not cached.
    ///
    /// Cacache verifies SSRI integrity on every read.
    pub async fn get(&self, prefix: &str, key: &str) -> Result<Option<Vec<u8>>, BlobCacheError> {
        validate_key(prefix, key)?;
        let cache_key = format!("{prefix}{key}");
        match cacache::read(&self.cache_dir, &cache_key).await {
            Ok(data) => Ok(Some(data)),
            Err(cacache::Error::EntryNotFound(_, _)) => Ok(None),
            Err(e) => {
                // Integrity failure or I/O error — remove corrupt entry.
                tracing::warn!(
                    target: "chanora_cache",
                    key = %cache_key,
                    error = %e,
                    "cache read failed; removing entry"
                );
                let _ = cacache::remove(&self.cache_dir, &cache_key).await;
                Ok(None)
            }
        }
    }
    /// Delete a specific blob.
    pub async fn remove(&self, prefix: &str, key: &str) -> Result<(), BlobCacheError> {
        validate_key(prefix, key)?;
        let cache_key = format!("{prefix}{key}");
        cacache::remove(&self.cache_dir, &cache_key)
            .await
            .map_err(|e| BlobCacheError::Io(format!("cacache remove: {e}")))?;
        Ok(())
    }
    /// Delete all blobs.
    pub async fn clear(&self) -> Result<(), BlobCacheError> {
        let path = self.cache_dir.clone();
        tokio::task::spawn_blocking(move || {
            if path.exists() {
                std::fs::remove_dir_all(&path)
                    .map_err(|e| BlobCacheError::Io(format!("clear cache: {e}")))?;
                std::fs::create_dir_all(&path)
                    .map_err(|e| BlobCacheError::Io(format!("recreate cache dir: {e}")))?;
            }
            Ok(())
        })
        .await
        .map_err(|e| BlobCacheError::Io(format!("clear task: {e}")))?
    }
    /// Return total bytes used by all blobs.
    ///
    /// Walks cacache entries and sums sizes.
    pub async fn total_size(&self) -> Result<u64, BlobCacheError> {
        let cache_dir = self.cache_dir.clone();
        tokio::task::spawn_blocking(move || {
            let mut total: u64 = 0;
            for entry in cacache::list_sync(&cache_dir) {
                match entry {
                    Ok(meta) => total += meta.size as u64,
                    Err(e) => {
                        tracing::warn!(
                            target: "chanora_cache",
                            error = %e,
                            "skipping bad entry during size scan"
                        );
                    }
                }
            }
            Ok(total)
        })
        .await
        .map_err(|e| BlobCacheError::Io(format!("total_size task: {e}")))?
    }
    /// Evict oldest entries by timestamp until total size is under
    /// `max_bytes`. Call on startup or periodically. No-op if
    /// `max_bytes` is 0.
    pub async fn evict(&self) -> Result<(), BlobCacheError> {
        if self.max_bytes == 0 {
            return Ok(());
        }
        let cache_dir = self.cache_dir.clone();
        let max_bytes = self.max_bytes;
        tokio::task::spawn_blocking(move || {
            let mut entries: Vec<(String, usize, u128)> = Vec::new();
            for entry in cacache::list_sync(&cache_dir) {
                match entry {
                    Ok(meta) => {
                        entries.push((meta.key, meta.size, meta.time));
                    }
                    Err(e) => {
                        tracing::warn!(
                            target: "chanora_cache",
                            error = %e,
                            "skipping bad entry during eviction scan"
                        );
                    }
                }
            }
            let total: usize = entries.iter().map(|(_, s, _)| *s).sum();
            if total as u64 <= max_bytes {
                return Ok(());
            }
            entries.sort_by_key(|(_, _, t)| *t);
            let mut freed: usize = 0;
            let target = total - max_bytes as usize;
            for (key, size, _) in entries {
                if freed >= target {
                    break;
                }
                let _ = cacache::remove_sync(&cache_dir, &key);
                freed += size;
            }
            tracing::info!(
                target: "chanora_cache",
                freed_bytes = freed,
                "evicted oldest blobs"
            );
            Ok(())
        })
        .await
        .map_err(|e| BlobCacheError::Io(format!("evict task: {e}")))?
    }
 }
 /// Validate key format to prevent malformed entries.
 fn validate_key(prefix: &str, key: &str) -> Result<(), BlobCacheError> {
    if !matches!(prefix, PREFIX_AVATAR | PREFIX_ICON) {
        return Err(BlobCacheError::InvalidKey(format!("bad prefix: {prefix}")));
    }
    match prefix {
        PREFIX_AVATAR => {
            // MD5 hex = exactly 32 hex chars.
            if key.len() != 32 || !key.chars().all(|c| c.is_ascii_hexdigit()) {
                return Err(BlobCacheError::InvalidKey(format!(
                    "avatar key must be 32 hex chars, got: {key}"
                )));
            }
        }
        PREFIX_ICON => {
            // Unsigned CRC32 = decimal digits.
            if key.is_empty() || !key.chars().all(|c| c.is_ascii_digit()) {
                return Err(BlobCacheError::InvalidKey(format!(
                    "icon key must be decimal digits, got: {key}"
                )));
            }
        }
        _ => unreachable!(),
    }
    Ok(())
 }
 #[cfg(test)]
 mod tests {
    use super::*;
    fn tempdir() -> tempfile::TempDir {
        tempfile::Builder::new()
            .prefix("chanora_cache_test_")
            .tempdir()
            .unwrap()
    }
    #[tokio::test]
    async fn put_get_roundtrip() {
        let tmp = tempdir();
        let cache = BlobCache::new(&tmp, 0).unwrap();
        assert!(cache
            .get(PREFIX_AVATAR, "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6")
            .await
            .unwrap()
            .is_none());
        cache
            .put(PREFIX_AVATAR, "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6", b"avatar-bytes")
            .await
            .unwrap();
        let data = cache
            .get(PREFIX_AVATAR, "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6")
            .await
            .unwrap();
        assert_eq!(data.as_deref(), Some(b"avatar-bytes".as_slice()));
    }
    #[tokio::test]
    async fn get_missing_returns_none() {
        let tmp = tempdir();
        let cache = BlobCache::new(&tmp, 0).unwrap();
        assert!(cache
            .get(PREFIX_AVATAR, "00000000000000000000000000000000")
            .await
            .unwrap()
            .is_none());
    }
    #[tokio::test]
    async fn clear_removes_all() {
        let tmp = tempdir();
        let cache = BlobCache::new(&tmp, 0).unwrap();
        cache
            .put(PREFIX_AVATAR, "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6", b"data")
            .await
            .unwrap();
        cache.put(PREFIX_ICON, "12345", b"icon").await.unwrap();
        cache.clear().await.unwrap();
        assert_eq!(cache.total_size().await.unwrap(), 0);
    }
    #[tokio::test]
    async fn total_size_accounts_for_all_entries() {
        let tmp = tempdir();
        let cache = BlobCache::new(&tmp, 0).unwrap();
        cache
            .put(PREFIX_AVATAR, "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6", b"12345")
            .await
            .unwrap();
        cache.put(PREFIX_ICON, "99999", b"12").await.unwrap();
        assert_eq!(cache.total_size().await.unwrap(), 5 + 2);
    }
    #[tokio::test]
    async fn invalid_key_rejected() {
        let tmp = tempdir();
        let cache = BlobCache::new(&tmp, 0).unwrap();
        // Too short for MD5.
        assert!(cache.put(PREFIX_AVATAR, "abc", b"data").await.is_err());
        // Non-hex in MD5.
        assert!(cache
            .put(PREFIX_AVATAR, "g".repeat(32).as_str(), b"data")
            .await
            .is_err());
        // Non-digit in icon key.
        assert!(cache.put(PREFIX_ICON, "12a45", b"data").await.is_err());
        // Bad prefix.
        assert!(cache.put("xx_", "abc", b"data").await.is_err());
    }
    #[tokio::test]
    async fn evict_deletes_oldest_until_under_cap() {
        let tmp = tempdir();
        // 10 byte cap.
        let cache = BlobCache::new(&tmp, 10).unwrap();
        cache
            .put(
                PREFIX_AVATAR,
                "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6",
                b"12345678",
            )
            .await
            .unwrap(); // 8 bytes
        tokio::time::sleep(std::time::Duration::from_millis(50)).await;
        cache
            .put(PREFIX_ICON, "11111", b"12345")
            .await
            .unwrap(); // 5 bytes → total 13, over cap
        cache.evict().await.unwrap();
        // Oldest (avatar) should be evicted.
        assert!(cache
            .get(PREFIX_AVATAR, "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6")
            .await
            .unwrap()
            .is_none());
        assert!(cache.get(PREFIX_ICON, "11111").await.unwrap().is_some());
    }
    #[tokio::test]
    async fn remove_deletes_entry() {
        let tmp = tempdir();
        let cache = BlobCache::new(&tmp, 0).unwrap();
        cache
            .put(PREFIX_AVATAR, "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6", b"data")
            .await
            .unwrap();
        cache
            .remove(PREFIX_AVATAR, "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6")
            .await
            .unwrap();
        assert!(cache
            .get(PREFIX_AVATAR, "a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6")
            .await
            .unwrap()
            .is_none());
    }
 }
@@ -24,6 +24,7 @@ use base64::prelude::*;
 use chanora_resolver::ChanoraResolver;
 use futures::prelude::*;
 use std::collections::HashMap;
 use tokio::io::AsyncReadExt;
 use tokio::sync::{mpsc, oneshot};
 use tracing::{info, warn};
@@ -32,7 +33,8 @@ use tsclientlib::messages::s2c::{InClientDbInfoPart, InMessage};
 use tsclientlib::prelude::*;
 use tsclientlib::{
    ChannelId as TsChannelId, ClientId as TsClientId, Connection, ConnectionStats,
-    DisconnectOptions, Identity, MessageHandle, OutCommandExt, StreamItem, Version,
+    DisconnectOptions, FileDownloadResult, FiletransferHandle, Identity, MessageHandle,
    OutCommandExt, StreamItem, Version,
 };
 use tsproto_packets::packets::{Direction, Flags, InAudioBuf, OutCommand, OutPacket, PacketType};
 use tsproto_types::ClientType;
@@ -60,6 +62,9 @@ type PendingMoves = HashMap<
    ),
 >;
 type PendingDownloads =
    HashMap<FiletransferHandle, oneshot::Sender<Result<Vec<u8>, ProtocolError>>>;
 struct EventChannels {
    voice_in: mpsc::Sender<InboundVoice>,
    chat: mpsc::Sender<ChatMessage>,
@@ -207,6 +212,10 @@ enum Request {
        client_id: u64,
        reply: oneshot::Sender<Result<ClientProfile, ProtocolError>>,
    },
    DownloadFile {
        path: String,
        reply: oneshot::Sender<Result<Vec<u8>, ProtocolError>>,
    },
 }
 /// Why a [`ProtocolClient`] task ended. Distinguishes a user-driven
@@ -366,6 +375,26 @@ impl ProtocolClient {
            .map_err(|_| ProtocolError::Lost("client_profile reply dropped".to_string()))?
    }
    async fn download_file(&self, path: String) -> Result<Vec<u8>, ProtocolError> {
        let (tx, rx) = oneshot::channel();
        self.tx
            .send(Request::DownloadFile { path, reply: tx })
            .await
            .map_err(|_| ProtocolError::Lost("connection task is gone".to_string()))?;
        rx.await
            .map_err(|_| ProtocolError::Lost("download_file reply dropped".to_string()))?
    }
    /// Download the current avatar bytes for a TeamSpeak client UID.
    pub async fn download_avatar(&self, client_uid: &str) -> Result<Vec<u8>, ProtocolError> {
        self.download_file(avatar_download_path(client_uid)).await
    }
    /// Download the current channel/server icon bytes for an icon id.
    pub async fn download_icon(&self, icon_id: u64) -> Result<Vec<u8>, ProtocolError> {
        self.download_file(icon_download_path(icon_id)).await
    }
    /// Disconnect cleanly. Blocks until the task exits.
    pub async fn disconnect(self) {
        let (tx, rx) = oneshot::channel();
@@ -713,6 +742,7 @@ async fn connection_task(
    // deadline so a server that never replies doesn't leak the
    // reply channel — at most 3 s of pending state per move.
    let mut pending_moves: PendingMoves = HashMap::new();
    let mut pending_downloads: PendingDownloads = HashMap::new();
    let mut voice_activity: HashMap<u64, Instant> = HashMap::new();
    let mut poke_limiter = PokeLimiter::new();
@@ -737,6 +767,12 @@ async fn connection_task(
                StreamItem::Audio(buf) => {
                    handle_audio_stream_item(&channels.voice_in, &mut voice_activity, buf).await;
                }
                StreamItem::FileDownload(handle, result) => {
                    handle_download_stream_item(&mut pending_downloads, handle, result).await;
                }
                StreamItem::FiletransferFailed(handle, error) => {
                    handle_download_failure(&mut pending_downloads, handle, error);
                }
                other => handle_non_audio_stream_item(
                    &con,
                    other,
@@ -843,12 +879,25 @@ async fn connection_task(
                    client_id,
                    &channels,
                    &mut pending_moves,
                    &mut pending_downloads,
                    &mut voice_activity,
                    &mut poke_limiter,
                )
                .await;
                let _ = reply.send(r);
            }
            Ok(Request::DownloadFile { path, reply }) => {
                match con.download_file(TsChannelId(0), &path, None, None) {
                    Ok(handle) => {
                        pending_downloads.insert(handle, reply);
                    }
                    Err(e) => {
                        let _ = reply.send(Err(ProtocolError::FileTransfer(format!(
                            "start download {path}: {e}"
                        ))));
                    }
                }
            }
            Ok(Request::Disconnect(reply)) => {
                let _ = con.disconnect(DisconnectOptions::new());
                bounded_drain_stream(con.events(), DISCONNECT_EVENT_DRAIN_TIMEOUT).await;
@@ -1024,6 +1073,47 @@ fn handle_non_audio_stream_item(
    }
 }
 async fn handle_download_stream_item(
    pending_downloads: &mut PendingDownloads,
    handle: FiletransferHandle,
    result: FileDownloadResult,
 ) {
    if let Some(reply) = pending_downloads.remove(&handle) {
        let _ = reply.send(read_download_bytes(result).await);
    }
 }
 fn handle_download_failure(
    pending_downloads: &mut PendingDownloads,
    handle: FiletransferHandle,
    error: tsclientlib::Error,
 ) {
    if let Some(reply) = pending_downloads.remove(&handle) {
        let _ = reply.send(Err(ProtocolError::FileTransfer(error.to_string())));
    }
 }
 const MAX_DOWNLOAD_SIZE: u64 = 10 * 1024 * 1024;
 async fn read_download_bytes(result: FileDownloadResult) -> Result<Vec<u8>, ProtocolError> {
    if result.size > MAX_DOWNLOAD_SIZE {
        return Err(ProtocolError::FileTransfer(format!(
            "download too large: {} bytes (max {})",
            result.size, MAX_DOWNLOAD_SIZE
        )));
    }
    let size = usize::try_from(result.size).map_err(|_| {
        ProtocolError::FileTransfer(format!("download too large to buffer: {} bytes", result.size))
    })?;
    let mut stream = result.stream;
    let mut bytes = vec![0_u8; size];
    stream
        .read_exact(&mut bytes)
        .await
        .map_err(|e| ProtocolError::FileTransfer(e.to_string()))?;
    Ok(bytes)
 }
 async fn resolve_server_socket(address: &str) -> Result<SocketAddr, ProtocolError> {
    let resolver = ChanoraResolver::new().map_err(|err| ProtocolError::DnsFailed {
        host: address.to_string(),
@@ -1174,6 +1264,7 @@ async fn fetch_client_profile(
    client_id: u64,
    channels: &EventChannels,
    pending_moves: &mut PendingMoves,
    pending_downloads: &mut PendingDownloads,
    voice_activity: &mut HashMap<u64, Instant>,
    poke_limiter: &mut PokeLimiter,
 ) -> Result<ClientProfile, ProtocolError> {
@@ -1220,6 +1311,7 @@ async fn fetch_client_profile(
            build_command("servergrouplist", &[], &[]),
            channels,
            pending_moves,
            pending_downloads,
            voice_activity,
            poke_limiter,
        )
@@ -1231,6 +1323,7 @@ async fn fetch_client_profile(
            build_command("channelgrouplist", &[], &[]),
            channels,
            pending_moves,
            pending_downloads,
            voice_activity,
            poke_limiter,
        )
@@ -1246,6 +1339,7 @@ async fn fetch_client_profile(
            ),
            channels,
            pending_moves,
            pending_downloads,
            voice_activity,
            poke_limiter,
        )
@@ -1265,6 +1359,7 @@ async fn fetch_client_profile(
            build_command("getconnectioninfo", &[("clid", client_id.to_string())], &[]),
            channels,
            pending_moves,
            pending_downloads,
            voice_activity,
            poke_limiter,
        )
@@ -1285,6 +1380,7 @@ async fn fetch_client_profile(
            database_id,
            channels,
            pending_moves,
            pending_downloads,
            voice_activity,
            poke_limiter,
        )
@@ -1448,6 +1544,7 @@ async fn request_messages(
    command: OutCommand,
    channels: &EventChannels,
    pending_moves: &mut PendingMoves,
    pending_downloads: &mut PendingDownloads,
    voice_activity: &mut HashMap<u64, Instant>,
    poke_limiter: &mut PokeLimiter,
 ) -> Result<Vec<InMessage>, ProtocolError> {
@@ -1485,6 +1582,12 @@ async fn request_messages(
            StreamItem::Audio(buf) => {
                handle_audio_stream_item(&channels.voice_in, voice_activity, buf).await;
            }
            StreamItem::FileDownload(handle, result) => {
                handle_download_stream_item(pending_downloads, handle, result).await;
            }
            StreamItem::FiletransferFailed(handle, error) => {
                handle_download_failure(pending_downloads, handle, error);
            }
            other => handle_non_audio_stream_item(
                con,
                other,
@@ -1503,6 +1606,7 @@ async fn request_client_db_info(
    dbid: tsclientlib::ClientDbId,
    channels: &EventChannels,
    pending_moves: &mut PendingMoves,
    pending_downloads: &mut PendingDownloads,
    voice_activity: &mut HashMap<u64, Instant>,
    poke_limiter: &mut PokeLimiter,
 ) -> Result<InClientDbInfoPart, ProtocolError> {
@@ -1511,6 +1615,7 @@ async fn request_client_db_info(
        build_command("clientdbinfo", &[("cldbid", dbid.0.to_string())], &[]),
        channels,
        pending_moves,
        pending_downloads,
        voice_activity,
        poke_limiter,
    )
@@ -1568,6 +1673,14 @@ fn uid_to_avatar_path(uid_b64: &str) -> String {
    rendered
 }
 fn avatar_download_path(client_uid: &str) -> String {
    format!("/avatar_{}", uid_to_avatar_path(client_uid))
 }
 fn icon_download_path(icon_id: u64) -> String {
    format!("/icon_{icon_id}")
 }
 fn find_client_by_id<'a>(
    clients: impl IntoIterator<Item = &'a Client>,
    client_id: u64,
@@ -1951,10 +2064,11 @@ const _: () = {
 #[cfg(test)]
 mod tests {
    use super::{
-        bounded_drain_stream, client_profile_refresh_plan, drain_voice_packets_for_tick,
+        avatar_download_path, bounded_drain_stream, client_profile_refresh_plan,
-        is_server_query_client_type, send_with_timeout, server_socket_from_config,
+        drain_voice_packets_for_tick, icon_download_path, is_server_query_client_type,
-        sort_channels_tree_by, std_duration_millis, ConnectConfig, ProtocolClient, Request,
+        send_with_timeout, server_socket_from_config, sort_channels_tree_by,
-        SendTimeoutError, DISCONNECT_REPLY_TIMEOUT,
+        std_duration_millis, ConnectConfig, ProtocolClient, Request, SendTimeoutError,
        DISCONNECT_REPLY_TIMEOUT,
    };
    use futures::stream;
    use std::time::Duration;
@@ -2052,6 +2166,16 @@ mod tests {
        assert!(plan.needs_channel_groups);
    }
    #[test]
    fn avatar_download_path_uses_uid_hex_encoding() {
        assert_eq!(avatar_download_path("AQID"), "/avatar_abacad");
    }
    #[test]
    fn icon_download_path_uses_unsigned_icon_id() {
        assert_eq!(icon_download_path(42), "/icon_42");
    }
    #[test]
    fn channel_sort_linked_list_under_one_parent() {
        // Server emits four root-level channels in arbitrary HashMap
@@ -115,4 +115,8 @@ pub enum ProtocolError {
    /// should never see this; if they do, it is a mapping bug here.
    #[error("protocol backend: {0}")]
    Backend(String),
    /// A file transfer failed while downloading protocol-owned assets.
    #[error("file transfer failed: {0}")]
    FileTransfer(String),
 }
@@ -0,0 +1,737 @@
 # File Transfer Design
 **Date:** 2026-06-10
 **Status:** Draft for review
 **Scope:** Download files from TeamSpeak-compatible servers via the native client protocol, starting with avatars and icons.
 **Direct upstream source:** `docs/architecture/sad.md` (SAD-067, SDD-MOD-009)
 ## 1. Goal
 Chanora needs to download files stored on TeamSpeak-compatible servers. The most visible use cases are client avatars and server/channel/client icons. The file transfer mechanism is also used for channel file browser features, but this document scopes the initial design to avatar and icon retrieval only.
 This document describes:
 - How the TeamSpeak file transfer protocol works.
 - How `tsclientlib` exposes it.
 - How Chanora should integrate it following the existing protocol adapter pattern.
 - How the result flows through the bridge to the Flutter UI layer.
 Upload, channel file browsing, and file deletion are explicitly out of scope for the initial implementation.
 ## 2. Protocol Background
 ### 2.1 Two-Phase Transfer
 TeamSpeak file transfer is a two-phase process:
 1. **Command phase** — The client sends a command over the main encrypted UDP connection to request a transfer token (`ftkey`).
 2. **Transfer phase** — The client opens a separate TCP connection to the server's file transfer port (default `30033`) and sends the `ftkey` to authenticate the transfer. Raw bytes flow over this TCP stream.
 ### 2.2 Relevant ServerQuery Commands
 | Command | Direction | Purpose |
 |---|---|---|
 | `ftinitdownload` | Client → Server | Initialize a download. Returns `ftkey`, `port`, `size`. |
 | `ftgetfileinfo` | Client → Server | Get metadata for one or more files. |
 | `ftgetfilelist` | Client → Server | List files in a channel's file repository. |
 | `ftinitupload` | Client → Server | Initialize an upload. |
 | `ftlist` | Client → Server | List active file transfers. |
 | `ftstop` | Client → Server | Stop a running transfer. |
 | `ftdeletefile` | Client → Server | Delete a file. |
 | `ftcreatedir` | Client → Server | Create a directory. |
 | `ftrenamefile` | Client → Server | Rename or move a file. |
 Initial scope uses only `ftinitdownload` and `ftgetfileinfo`.
 ### 2.3 File Paths
 Files are addressed by a path scoped to a channel ID (`cid`):
 - `cid=0` — Server-level file repository. Avatars and icons live here.
 - `cid=N` (non-zero) — Channel-specific file repository.
 Avatar path: `/avatar_<hex>` where `<hex>` is derived from the client's unique identifier (UID). Each byte of the base64-decoded UID is split into two nibbles, and each nibble maps to a letter `a` through `p` (0→a, 1→b, ..., 15→p).
 Icon path: `/icon_<id>` where `<id>` is the icon's signed 64-bit integer ID. If negative, treat as unsigned for the path.
 ### 2.4 `ftinitdownload` Command
 ```
 ftinitdownload clientftfid={id} name={path} cid={channelId} cpw={password} seekpos={seek} proto=0
 ```
 Parameters:
 | Parameter | Type | Description |
 |---|---|---|
 | `clientftfid` | `u16` | Arbitrary client-side transfer ID. |
 | `name` | `string` | File path, e.g. `/avatar_abcdef`. |
 | `cid` | `ChannelId` | Channel scope (0 = server). |
 | `cpw` | `string` | Channel password. Empty for server-level. |
 | `seekpos` | `u64` | Resume offset. 0 for a fresh download. |
 | `proto` | `u8` | Protocol version. Always 0. |
 Server response:
 | Field | Type | Description |
 |---|---|---|
 | `clientftfid` | `u16` | Echo of the client transfer ID. |
 | `serverftfid` | `u16` | Server-side transfer ID. |
 | `ftkey` | `string` | One-time transfer key (hex). |
 | `port` | `u16` | File transfer TCP port (usually 30033). |
 | `size` | `u64` | File size in bytes. |
 | `proto` | `u8` | Protocol version echo. |
 | `ip` | `string` (optional) | Override IP for the TCP connection. |
 ### 2.5 TCP Transfer
 After receiving the `ftkey`, the client:
 1. Opens a TCP connection to `server_ip:port`.
 2. Sends `ftkey` followed by a newline.
 3. Reads exactly `size` bytes of raw file data.
 4. Closes the TCP connection.
 ### 2.6 Permissions
 File transfer requires the following permissions on the server:
 | Permission | Needed for |
 |---|---|
 | `i_ft_file_download_power` | Downloading files. |
 | `i_ft_needed_file_download_power` | Required download power on the channel/server. |
 | `b_ft_ignore_password` | Bypassing channel passwords (not needed for avatars). |
 Avatar downloads typically require only basic download power because avatars are in the server-level repository (`cid=0`), which is generally accessible.
 ### 2.7 Avatar Detection
 When a client connects or updates, the server sends `client_flag_avatar` as a string (the avatar hash). If non-empty, the client has an avatar. The avatar is downloaded from `/avatar_<hex>` where `<hex>` is computed from the client's UID (not from the hash string itself — the hash is just a presence indicator).
 ## 3. tsclientlib Support
 `tsclientlib` implements file transfer natively. The library handles the entire command + TCP flow internally:
 ### 3.1 Public API
 ```rust
 // tsclientlib/src/lib.rs (relevant signatures)
 impl Connection {
    pub fn download_file(
        &mut self,
        channel_id: ChannelId,
        path: &str,
        channel_password: Option<&str>,
        seek_position: Option<u64>,
    ) -> Result<FiletransferHandle>;
    pub fn upload_file(
        &mut self,
        channel_id: ChannelId,
        path: &str,
        channel_password: Option<&str>,
        size: u64,
        overwrite: bool,
        resume: bool,
    ) -> Result<FiletransferHandle>;
 }
 ```
 `download_file` sends the `ftinitdownload` command and returns a `FiletransferHandle(u16)` immediately. The actual transfer completes asynchronously.
 ### 3.2 Stream Items
 The connection's event stream emits:
 | StreamItem | When | Data |
 |---|---|---|
 | `StreamItem::FileDownload(FileDownloadResult)` | Server responds with `ftkey`; TCP connected and `ftkey` written | `{ size: u64, stream: TcpStream }` |
 | `StreamItem::FileUpload(FileUploadResult)` | Upload ready | `{ seek_position: u64, stream: TcpStream }` |
 | `StreamItem::FiletransferFailed(FiletransferHandle, Error)` | Transfer failed | Handle + error |
 When `FileDownload` fires, tsclientlib has already:
 1. Sent `ftinitdownload` over the encrypted UDP command channel.
 2. Received the `ftkey`, `port`, and `size` from the server.
 3. Opened a TCP connection to `server:port`.
 4. Written the `ftkey` to the TCP socket.
 The `TcpStream` in `FileDownloadResult` is ready to read; Chanora only needs to read exactly `size` bytes.
 ### 3.3 Avatar Helper
 `tsproto-types` provides `Uid::as_avatar()` which computes the avatar filename from a UID. Chanora's existing `uid_to_avatar_path()` in `adapter.rs` does the same thing independently.
 ### 3.4 Doc-Comment Examples
 tsclientlib's source contains usage examples in doc comments:
 ```rust
 /// Download an icon:
 /// con.download_file(ChannelId(0), &format!("/icon_{}", icon_id), None, None)
 /// Upload an avatar:
 /// con.upload_file(ChannelId(0), "/avatar", None, data.len() as u64, true, false)
 ```
 ## 4. Architecture Integration
 ### 4.1 Existing Pattern
 The protocol adapter (`crates/chanora_protocol`) uses a single tokio task that owns the `tsclientlib::Connection`. All operations follow this pattern:
 1. Define a `Request` enum variant with parameters and a `oneshot::Sender` for the reply.
 2. Send the request through the `mpsc` channel to the connection task.
 3. The connection task calls tsclientlib and resolves the oneshot.
 File transfer fits this pattern exactly. The only difference is that the result arrives asynchronously via `StreamItem::FileDownload` rather than immediately from the command call.
 ### 4.2 Design
 The file transfer integration adds:
 1. **`Request` variants** for file download.
 2. **A pending-downloads map** (`HashMap<FiletransferHandle, DownloadContext>`) in the connection task, mirroring the existing `pending_moves` pattern.
 3. **`StreamItem::FileDownload` and `StreamItem::FiletransferFailed`** handling in the event loop.
 4. **New DTOs** for file transfer results.
 5. **Convenience methods** on `ProtocolClient` for avatar and icon downloads.
 ### 4.3 Layer Responsibilities
 | Layer | Responsibility |
 |---|---|
 | `chanora_protocol` | Call `tsclientlib::download_file`, track pending transfers, read `TcpStream`, return bytes. No tsclientlib types leak. |
 | `chanora_core` | Orchestrate when to download (e.g., on profile fetch or on avatar cache miss). |
 | `chanora_bridge` | Expose typed `download_avatar` / `download_icon` commands to Flutter. |
 | Flutter UI | Call bridge, display with `Image.memory()`. Cache in memory/image cache. |
 ### 4.4 Error Mapping
 File transfer errors map to the existing `ProtocolError` variants:
 | tsclientlib error | ProtocolError |
 |---|---|
 | Permission denied (TS3 error code) | `ServerRejected { code, message }` |
 | File not found | `ServerRejected { code, message }` |
 | Network/TCP failure | `Backend(String)` |
 | Timeout | `Timeout` |
 | Connection lost mid-transfer | `Lost(String)` |
 ## 5. Detailed Design
 ### 5.1 New Types in `dto.rs`
 ```rust
 /// A downloaded file's raw content and metadata.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct DownloadedFile {
    /// Raw file bytes.
    pub data: Vec<u8>,
    /// The server path that was requested.
    pub path: String,
    /// Channel ID the file was downloaded from.
    pub channel_id: u64,
 }
 ```
 ### 5.2 New Request Variants in `adapter.rs`
 ```rust
 enum Request {
    // ... existing variants ...
    /// Download a file from the server's file repository.
    DownloadFile {
        /// Channel ID. 0 for server-level (avatars, icons).
        channel_id: u64,
        /// File path, e.g. "/avatar_abcdef" or "/icon_12345".
        path: String,
        /// Channel password. None for server-level files.
        channel_password: Option<String>,
        /// Reply channel for the result.
        reply: oneshot::Sender<Result<DownloadedFile, ProtocolError>>,
    },
 }
 ```
 ### 5.3 Pending Downloads Map
 ```rust
 type PendingDownloads = HashMap<tsclientlib::FiletransferHandle, PendingDownload>;
 struct PendingDownload {
    path: String,
    channel_id: u64,
    reply: oneshot::Sender<Result<DownloadedFile, ProtocolError>>,
 }
 ```
 ### 5.4 Event Loop Handling
 In the connection task's main loop, add handling for file transfer stream items:
 ```rust
 // In handle_non_audio_stream_item or in the main loop:
 StreamItem::FileDownload(result) => {
    // result: FileDownloadResult { size, stream }
    // Look up the handle in pending_downloads
    // Use tokio::io::AsyncReadExt::read_exact to read 'size' bytes
    // Resolve the oneshot with DownloadedFile
 }
 StreamItem::FiletransferFailed(handle, error) => {
    // Look up the handle in pending_downloads
    // Resolve the oneshot with ProtocolError::Backend
 }
 ```
 The TCP read from the `TcpStream` is an async operation. Since the connection task already runs in a tokio context, the read can be done inline. However, for large files this would block the main event loop. Two approaches:
 **Option A: Read inline (simple, good for small files like avatars)**
 Avatars are typically under 100 KB. Reading them inline in the event loop is acceptable and avoids complexity.
 **Option B: Spawn a reader task**
 For future channel-file-browser support with potentially large files, spawn a separate tokio task that reads the stream and sends the result back.
 **Recommendation:** Start with Option A. The initial scope is avatars and icons (small files). Refactor to Option B when channel file browsing is implemented.
 ### 5.5 Request Handling
 When the connection task receives `Request::DownloadFile`:
 ```rust
 Ok(Request::DownloadFile { channel_id, path, channel_password, reply }) => {
    let ts_channel_id = TsChannelId(channel_id);
    match con.download_file(ts_channel_id, &path, channel_password.as_deref(), None) {
        Ok(handle) => {
            pending_downloads.insert(handle, PendingDownload {
                path,
                channel_id,
                reply,
            });
        }
        Err(e) => {
            let _ = reply.send(Err(ProtocolError::Backend(
                format!("download_file init: {e}")
            )));
        }
    }
 }
 ```
 ### 5.6 Public API on `ProtocolClient`
 ```rust
 impl ProtocolClient {
    /// Download a file from the server's file repository.
    /// `channel_id` 0 means server-level (avatars, icons).
    pub async fn download_file(
        &self,
        channel_id: u64,
        path: String,
        channel_password: Option<String>,
    ) -> Result<DownloadedFile, ProtocolError> {
        let (tx, rx) = oneshot::channel();
        self.tx
            .send(Request::DownloadFile { channel_id, path, channel_password, reply: tx })
            .await
            .map_err(|_| ProtocolError::Lost("connection task is gone".to_string()))?;
        rx.await
            .map_err(|_| ProtocolError::Lost("download_file reply dropped".to_string()))?
    }
    /// Download a client's avatar image. Returns raw image bytes.
    /// Pass the `avatar_path` from `ClientProfile`.
    pub async fn download_avatar(
        &self,
        avatar_path: String,
    ) -> Result<DownloadedFile, ProtocolError> {
        self.download_file(0, avatar_path, None).await
    }
    /// Download a server, channel, or client icon by its icon ID.
    pub async fn download_icon(
        &self,
        icon_id: i64,
    ) -> Result<DownloadedFile, ProtocolError> {
        let unsigned_id = icon_id as u64;
        let path = format!("/icon_{}", unsigned_id);
        self.download_file(0, path, None).await
    }
 }
 ```
 ### 5.7 Exports in `lib.rs`
 ```rust
 pub use dto::DownloadedFile;
 ```
 ### 5.8 Bridge Layer
 In `crates/chanora_bridge/src/api.rs`, add:
 ```rust
 pub async fn download_avatar(&self, avatar_path: String) -> Result<Vec<u8>, BridgeError> {
    self.protocol
        .download_avatar(avatar_path)
        .await
        .map(|file| file.data)
        .map_err(BridgeError::Protocol)
 }
 ```
 ### 5.9 Flutter Integration
 Flutter side:
 1. Call `clientProfile()` to get `ClientProfile` (already exists).
 2. Check if `avatarPath` is non-empty.
 3. Call bridge `downloadAvatar(avatarPath)` to get `Uint8List`.
 4. Display with `Image.memory(bytes)`.
 Caching strategy:
 - In-memory: Use Flutter's standard `ImageCache` or a simple `Map<String, Uint8List>` keyed by avatar path.
 - Disk: Consider caching to local storage for offline display. This is a follow-up decision, not MVP scope.
 - The avatar path already encodes the UID, so it can serve as a cache key.
 ## 6. Avatar Path Computation
 Chanora already has this implemented in `adapter.rs`:
 ```rust
 fn uid_to_avatar_path(uid_b64: &str) -> String {
    let decoded = BASE64_STANDARD.decode(uid_b64).unwrap_or_default();
    let mut rendered = String::with_capacity(decoded.len() * 2);
    for byte in decoded {
        rendered.push((b'a' + (byte >> 4)) as char);
        rendered.push((b'a' + (byte & 0x0f)) as char);
    }
    rendered
 }
 ```
 This maps each nibble to `a` through `p` (0→a, 1→b, ..., 15→p), matching the canonical TeamSpeak implementation.
 The full avatar path is constructed as:
 ```rust
 let avatar_path = if client.avatar_hash.is_empty() || unique_id.is_empty() {
    String::new()
 } else {
    format!("/avatar_{}", uid_to_avatar_path(&unique_id))
 };
 ```
 This is already correct and used in `ClientProfile.avatar_path`. No changes needed.
 ## 7. Threading and Concurrency
 | Concern | Design |
 |---|---|
 | TCP read blocking the event loop | For avatar/icon sizes (< 100 KB typically), inline async read is acceptable. Spawn a reader task for larger files when channel file browsing is added. |
 | Multiple concurrent downloads | `pending_downloads` is a HashMap keyed by `FiletransferHandle`. Multiple downloads can be in flight simultaneously. tsclientlib assigns unique handles. |
 | Download timeout | Add a deadline to pending downloads (e.g., 30 seconds). Sweep expired entries similar to the existing `pending_moves` sweep. |
 | Cancellation on disconnect | When the connection task exits, all pending oneshot senders are dropped, which resolves the caller's await with a `RecvError`. The caller maps this to `ProtocolError::Lost`. |
 ## 8. Diagnostic and Security Considerations
 ### 8.1 Diagnostic Redaction
 - File transfer paths may contain user-identifying information (UID-derived avatar names). These should be registered for diagnostic redaction if they appear in log output.
 - File contents (avatar images) must not appear in log output or diagnostic exports.
 ### 8.2 Security
 - The `ftkey` is a one-time token and must not be logged.
 - TCP file transfer connections are not encrypted. This is a TeamSpeak protocol limitation, not a Chanora design choice. Avatar data is public (visible to anyone on the server), so the risk is acceptable.
 - File download does not require secrets beyond the existing authenticated connection.
 ### 8.3 Privacy
 - Avatar downloads reveal to the server that the user is viewing a specific client's avatar. This is inherent in the protocol.
 - Chanora should not download avatars proactively for all clients. Download only when the UI needs to display a specific avatar (lazy/on-demand).
 ## 9. Out of Scope
 The following are explicitly deferred:
 - File upload (avatar upload, channel file upload).
 - Channel file browser (listing, creating directories, deleting, renaming).
 - Resumable downloads (seek position > 0).
 - File transfer progress reporting.
 - myTeamSpeak avatar resolution (the `client_myteamspeak_avatar` field).
 - In-memory hot cache in Rust (Flutter's `ImageCache` handles decoded image caching; add Rust-side layer only if profiling shows need).
 - Upload, file browser, and channel file management.
 ## 10. Cache Architecture
 ### 10.1 Layer Ownership
 | Layer | Responsibility | Storage |
 |---|---|---|
 | `chanora_protocol` | Download raw bytes from server. No caching logic. | None |
 | `chanora_cache` | Content-addressed blob store backed by `cacache`: crash-safe writes, SSRI integrity verification, key validation, eviction, clear. Separate crate from `chanora_storage`. | Platform cache directory |
 | `chanora_core` | Session-aware cache orchestration: check freshness, coalesce requests, rate-limit downloads, persist to disk via `chanora_cache`. | Delegates to `chanora_cache` |
 | `chanora_bridge` | Expose typed `download_avatar` / `clear_file_cache` / `file_cache_size` to Flutter. | None |
 | Flutter | Display via `Image.memory`. Standard `ImageCache` for hot memory caching. Evict from `ImageCache` when hash changes. | In-memory only |
 ### 10.2 Why Separate `chanora_cache` Crate
 `chanora_cache` is a separate crate from `chanora_storage` for three reasons:
 1. **Different durability semantics.** `chanora_storage` holds identity, bookmarks, and connection profiles — data the user explicitly created. `chanora_cache` holds downloaded blobs that are fully reconstructible from the server. Losing the cache is an inconvenience, not data loss.
 2. **Different backup semantics.** Cache should be excluded from backups; persistent storage should be included. Platform conventions (iOS `Library/Caches/` vs `Library/Application Support/`) reflect this distinction.
 3. **Different directory placement.** Cache lives in the platform's cache directory (OS may evict under storage pressure on mobile). Persistent storage lives in the support directory.
 The cache wraps the `cacache` crate for production-tested crash safety and integrity verification. It does not share `chanora_storage`'s crate or directory, and does not reimplement cacache's atomic write or content-addressing logic.
 ### 10.3 Why Hybrid (Rust Disk + Flutter Memory)
 - Flutter's built-in `ImageCache` is an LRU in-memory cache (default 1000 images / 100 MiB). It handles hot display caching automatically when you use `MemoryImage`.
 - Flutter has no built-in disk cache. `cached_network_image` / `flutter_cache_manager` are designed for HTTP URLs, not custom binary protocol data.
 - Rust already owns the protocol, the connection state, and the anti-flood budget. Putting disk cache here avoids a feedback loop across the bridge.
 ### 10.4 Cache Storage
 `chanora_cache` wraps the `cacache` crate for its on-disk storage. The physical layout is managed by `cacache`:
 ```
 <app_cache_dir>/chanora/
  blobs/                         ← cacache content store root
    content-v2/                  ← content-addressed by SHA-512
      <sha512-hex>/
        data                     ← raw blob bytes
    tmp/                         ← temp files (in-flight writes)
    index-v2/                    ← entry index (key → content mapping)
 ```
 Chanora's `BlobCache` maps protocol keys to `cacache` string keys:
 | Protocol key | cacache key | Example |
 |---|---|---|
 | Avatar MD5 | `"av_<md5hex>"` | `"av_a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6"` |
 | Icon CRC32 | `"ic_<crc32u>"` | `"ic_123456789"` |
 **Why `cacache`:**
 1. **Crash safety.** Production-tested atomic writes (temp → rename). Handles partial writes, power loss, crash mid-write. No custom crash safety code to maintain.
 2. **Integrity verification.** SSRI integrity check on every `read()`. Detects corruption, bit rot, partial writes automatically. Better than custom "delete on read failure".
 3. **Content dedup.** Same bytes stored once regardless of key. Same avatar on two servers = stored once automatically.
 4. **Less code to maintain.** ~120 LOC wrapper vs ~200 LOC custom implementation. Crash safety and integrity are the hard parts — `cacache` owns them.
 **Why no `<server_uid>` subdirectory:** The protocol uses content-addressed identifiers. `client_flag_avatar` is the MD5 of the avatar bytes — a given avatar hash always maps to the same bytes regardless of which server the user is on. Same avatar on two servers = same content = stored once by `cacache`. This is a deliberate dedup advantage over per-server namespacing.
 **Why no metadata sidecars:** Content is immutable (a given hash always maps to the same bytes). `cacache` manages its own entry index with timestamps. No custom metadata files needed.
 **Key validation rules:**
 | Prefix | Key format | Validation |
 |---|---|---|
 | `av_` | `av_<32 hex chars>` | MD5 is exactly 32 hex characters |
 | `ic_` | `ic_<1-10 digit number>` | CRC32 unsigned, 0–4294967295 |
 Keys failing validation are rejected at the `BlobCache` API boundary. This prevents path traversal or malformed filenames on disk.
 **Platform paths** (Flutter passes the base directory into Rust at startup, matching the existing `initStorage` pattern):
 | Platform | Cache directory |
 |---|---|
 | Android | `context.cacheDir/chanora/` (via `getCacheDir()`) |
 | iOS | `Library/Caches/chanora/` (via `getApplicationCacheDirectory()`) |
 | macOS | `~/Library/Caches/chanora/` |
 | Windows | `%LOCALAPPDATA%/chanora/cache/` |
 | Linux | `$XDG_CACHE_HOME/chanora/` or `~/.cache/chanora/` |
 Flutter already resolves platform-specific paths. The same `getApplicationCacheDirectory()` call that is available in `path_provider` across all Chanora target platforms should be used. This follows the existing pattern where `app_bootstrap.dart` calls `getApplicationSupportDirectory()` for persistent storage; avatar/icon cache uses the cache-equivalent directory instead.
 The cache init call is separate from storage init:
 ```rust
 // Bridge init (Flutter calls these at startup)
 pub fn init_storage(support_dir: String) -> Result<(), BridgeError>; // existing
 pub fn init_cache(cache_dir: String) -> Result<(), BridgeError>;     // new
 ```
 ### 10.5 Cache Freshness Strategy
 The `client_flag_avatar` field on each client is the authoritative freshness signal:
 ```
 On connect / on client list update:
  For each visible client with non-empty avatar_hash:
    cache_key = "av_<avatar_hash>"
    if cacache entry exists for "av_<avatar_hash>":
      use cached file (zero downloads)
    else:
      enqueue download for avatar_path with expected hash = avatar_hash
 On avatar_hash change for a client:
  The new hash produces a different cacache key.
  The old entry remains until eviction or manual clear.
  The new file is downloaded on demand.
 ```
 This means:
 - **First connect:** No cache hits. Downloads happen lazily as the UI requests avatars.
 - **Reconnect to same server:** All avatars hit cache instantly (hashes match keys). Zero downloads.
 - **User changes avatar:** New hash = new cache key. Old entry becomes orphan. New file downloads on next UI request.
 - **Same user on different server:** Same avatar hash = same cached file. Cross-server dedup for free.
 ### 10.6 Anti-Flood and Download Timing
 TeamSpeak servers enforce anti-flood rate limiting. Downloading all avatars eagerly on connect would trigger it on servers with many users.
 **Strategy: lazy + throttled prefetch**
 | Phase | What | Rate |
 |---|---|---|
 | Connect settle (first 2-5 s) | Do nothing. Let the initial state snapshot and channel tree arrive. | — |
 | After settle | UI requests avatars for visible clients in the current channel. These trigger downloads one at a time. | Max 1-2 concurrent downloads per server |
 | Channel switch | UI requests avatars for newly visible clients. | Same throttle |
 | Background prefetch (optional, future) | Low-priority downloads for clients in adjacent channels. | 1 request per 500 ms |
 **Anti-flood handling:**
 - If the server responds with an anti-flood error (TS3 error code `0x0701` = `client_could_not_be_banned` / flood-related), back off the download queue.
 - Implement a simple semaphore in `chanora_core`: max 1-2 concurrent downloads.
 - If a download gets a flood error, pause the queue for 5 seconds, then resume at reduced rate.
 ### 10.7 Retry on Failure
 | Failure type | Strategy |
 |---|---|
 | Transient (network timeout, TCP reset) | Retry with exponential backoff: 5 s, 30 s, 2 min, 10 min. Cap at 10 min. |
 | Server flood limit hit | Pause queue 5 s, then resume at reduced rate. Do not count as a per-file retry. |
 | Permission denied (no download power) | Do not retry. Record negative cache entry. Only retry if hash changes. |
 | File not found (avatar removed) | Do not retry. Record negative cache entry. Clear when hash changes or becomes empty. |
 | Connection lost | All pending downloads fail. On reconnect, cache check runs fresh with current hashes. |
 **Negative cache:** In-memory `HashMap<String, Instant>` with 5-minute TTL. Keys like `"av_<hash>"` or `"ic_<id>"` that received permanent errors are stored with an expiry. On lookup, expired entries are treated as absent. Cleared entirely on reconnect.
 ### 10.8 Request Coalescing
 Multiple UI widgets may request the same avatar simultaneously (e.g., channel list + chat view + client info sheet).
 **Pattern:** In `chanora_core`'s `FileTransferService`, maintain an in-flight map:
 ```rust
 HashMap<String, tokio::task::JoinHandle<Result<Vec<u8>, FileTransferError>>>
 ```
 - First request: start download, store handle.
 - Subsequent requests for same key: await the same handle.
 - When handle completes: write to cache, wake all waiters, remove from map.
 ### 10.9 Cache Eviction and Size Limits
 **MVP approach:**
 - No automatic size-based eviction in MVP. Avatars are small (typically 10-100 KB). Even 1000 avatars = ~50-100 MB.
 - Rely on platform cache directory semantics (OS may evict under storage pressure on mobile).
 - Old hash files accumulate but are harmless.
 **Post-MVP:**
 - `BlobCache::evict(max_bytes)` — walk `cacache::ls()` entries, sort by timestamp (oldest first), delete until total size < `max_bytes`. `cacache` manages timestamps internally. No metadata sidecars needed.
 - Or simpler: `BlobCache::evict_older_than(duration)` — delete entries with timestamp older than N days.
 - Call on startup and periodically (e.g., every 24 hours or on app resume).
 ### 10.10 User-Initiated Cache Clear
 Add a bridge method:
 ```rust
 pub fn clear_file_cache(&self) -> Result<(), BridgeError> {
    // Delete the entire blobs/ directory contents
    // Flutter evicts all avatar/icon-related entries from ImageCache
 }
 pub fn file_cache_size(&self) -> Result<u64, BridgeError> {
    // Walk blobs/ and sum file sizes
 }
 ```
 Flutter side:
 ```dart
 // In settings or storage management UI:
 onPressed: () async {
  await api.clearFileCache();
  PaintingBinding.instance.imageCache.clear();
 }
 ```
 This should be exposed in the app's settings UI under a "Clear cache" or "Storage management" section.
 ### 10.11 Storage Clear Across Servers
 Since the cache is flat with content-addressed keys (no server namespacing):
 - Connecting to a different server does not conflict — same avatar hash = same file.
 - Avatars unique to the old server remain cached. If a user on the new server has the same avatar (same hash), it hits cache instantly (cross-server dedup).
 - Cache clear removes all cached data regardless of which server it came from.
 ### 10.12 Flutter Display Strategy
 **Option A: Bytes across bridge (simpler, recommended for MVP)**
 Rust returns `Vec<u8>` across the bridge. Flutter uses `Image.memory(bytes)`.
 ```dart
 final bytes = await api.downloadAvatar(clientUid: uid);
 if (bytes != null && bytes.isNotEmpty) {
  return Image.memory(Uint8List.fromList(bytes));
 } else {
  return CircleAvatar(child: Text(initials)); // fallback
 }
 ```
 Flutter's `ImageCache` caches the decoded image in memory automatically. Same avatar bytes = cache hit in memory.
 **Option B: File path across bridge (better for large images, future)**
 Rust writes to disk and returns the file path. Flutter uses `FileImage`.
 ```dart
 final path = await api.getAvatarPath(avatarHash: hash);
 if (path != null) {
  return Image.file(File(path));
 } else {
  return CircleAvatar(child: Text(initials));
 }
 ```
 `FileImage` does not watch for file changes. When the hash changes, the UI must evict the old entry from `ImageCache` using `PaintingBinding.instance.imageCache.evict(key)`.
 **Recommendation:** Start with Option A for MVP. It avoids file-path cross-platform complications and works well for small avatar files. The bridge already returns `Vec<u8>` for the download result.
 ## 11. Implementation Sequence
 | Phase | Scope | What |
 |---|---|---|
 | Phase 1 | Protocol download | `Request::DownloadFile`, `StreamItem::FileDownload` handling, `ProtocolClient::download_avatar()` / `download_icon()`. No caching. |
 | Phase 2 | Bridge + Flutter display | Bridge `downloadAvatar()`, Flutter `Image.memory()`, initials fallback. Still no caching — every view re-downloads. |
 | Phase 3 | Rust disk cache | New `chanora_cache` crate: `cacache`-backed content-addressed blob store (`BlobCache`), key validation, mtime-based eviction, `init_cache` bridge call. |
 | Phase 4 | Session orchestration | `chanora_core` `FileTransferService`: request coalescing, rate limiter (semaphore), negative cache (5 min TTL), retry backoff. |
 | Phase 5 | Cache management | Bridge `clearFileCache()` + `fileCacheSize()`, Flutter settings UI, eviction on startup. |
 Phase 1 and 2 deliver visible value (avatars in the UI). Phase 3-5 add robustness.
 ## 12. References
 | Reference | Use |
 |---|---|
 | `ReSpeak/tsdeclarations` `Messages.toml` lines 828-830 | `ftinitdownload` command declaration |
 | `ReSpeak/tsdeclarations` `Messages.toml` lines 590 | `FileDownload` response structure |
 | `ReSpeak/tsdeclarations` `ts3protocol.md` | Low-level TeamSpeak protocol specification |
 | `ReSpeak/tsclientlib` `src/lib.rs` lines 956-1005 | `download_file` / `upload_file` public API |
 | `ReSpeak/tsclientlib` `src/lib.rs` lines 1371-1427 | `StreamItem::FileDownload` handling |
 | `ReSpeak/tsclientlib` `src/lib.rs` lines 1630-1672 | Outgoing init commands |
 | `Multivit4min/TS3-NodeJS-Library` `src/transport/FileTransfer.ts` | Reference TCP transfer implementation |
 | `Speckmops/ts3admin.class` `lib/ts3admin.class.php` lines 1352-1370 | Reference avatar download flow |
 | `docs/architecture/sad.md` SAD-067, SDD-MOD-009 | Protocol adapter boundary rules |
 | `crates/chanora_protocol/src/adapter.rs` lines 1561-1568 | Existing `uid_to_avatar_path` implementation |
@@ -0,0 +1,770 @@
 # File Transfer Cache Research
 **Date:** 2026-06-10
 **Status:** Research complete, design implications noted (updated with TeaSpeak server findings)
 **Companion to:** `docs/architecture/file-transfer-design.md`
 **Purpose:** Factual findings from protocol analysis, existing client implementations, and cross-platform research that inform the cache architecture decision.
 ---
 ## 1. TS3 Protocol Identity Semantics
 ### 1.1 Avatar Identity
 | Aspect | Value |
 |---|---|
 | Protocol field | `client_flag_avatar` |
 | Type | `TYPE_STRING` (TeaSpeakLibrary `PropertyDefinition.h:200`) |
 | Meaning | MD5 hash of the avatar file bytes |
 | Scope | Per-client per-server — a user can have different avatars on different servers |
 | Freshness | Automatically up-to-date for any client "in view" (`FLAG_CLIENT_VIEW`) |
 | Empty value | No avatar set |
 **Key fact:** Identical avatar image bytes produce the **same** `client_flag_avatar` hash on any TS3 server. The hash is a content fingerprint, not a server-assigned identifier.
 **Download path on server:** `/avatar_<base64HashClientUID>` — the filename is derived from the client's unique identifier (UID), not from the content hash. The content hash is communicated separately via `client_flag_avatar`.
 **Sources:**
 - TeaSpeakLibrary `PropertyDefinition.h:200`: `PropertyDescription{CLIENT_FLAG_AVATAR, "client_flag_avatar", "", TYPE_STRING, FLAG_CLIENT_VIEW | FLAG_SAVE | FLAG_USER_EDITABLE}`
 - TS3AudioBot avatar upload: computes MD5 of image bytes, then sets `client_flag_avatar` to that hash ([`TS3AudioBot/TSLib/TsBaseFunctions.cs:324-341`](https://github.com/Splamy/TS3AudioBot/blob/a69a38d8cba5a4d671dbe06505506f6b46f1d947/TSLib/TsBaseFunctions.cs#L324-L341))
 - TS3 NodeJS Library: avatar filename is `avatar_${clientBase64HashClientUID}` ([`TS3-NodeJS-Library/src/node/Client.ts:300-313`](https://github.com/Multivit4min/TS3-NodeJS-Library/blob/0c69b7ee80fa5b74e9175cf4ae3018346f7eb300/src/node/Client.ts#L300-L313))
 - TS3 PHP Framework: avatar name derivation from UID ([`ts3phpframework/src/Node/Client.php:288-307`](https://github.com/planetteamspeak/ts3phpframework/blob/87046b3d493c4d3d8064c639ea4269571192e476/src/Node/Client.php#L288-L307))
 ### 1.2 Icon Identity
 | Aspect | Value |
 |---|---|
 | Protocol fields | `channel_icon_id`, `client_icon_id`, `virtualserver_icon_id` |
 | Type | `TYPE_UNSIGNED_NUMBER` (TeaSpeakLibrary `PropertyDefinition.h:83,146,217`) |
 | Meaning | CRC32 (unsigned) of the icon file bytes |
 | Scope | Per-entity per-server — but CRC32 is content-derived |
 | Download path | `/icon_<unsigned_crc32>` |
 **Key fact:** Identical icon bytes produce the **same** CRC32 on any TS3 server. The icon ID is a content fingerprint. The upload process computes `crc32.unsigned(data)` and stores at `/icon_<id>`.
 **CRC32 collision caveat:** CRC32 is only 32 bits. Different icon content can theoretically produce the same CRC32. Qint's `filecache.rs` explicitly notes this: "there could be collisions because only CRC-32 is used." ForChanora's purposes (small icons, not security-critical), this is acceptable.
 **Sources:**
 - TeaSpeakLibrary `PropertyDefinition.h:83,146,217`: all icon IDs are `TYPE_UNSIGNED_NUMBER`
 - TS3 NodeJS Library `uploadIcon()`: computes `crc32.unsigned(data)`, uploads to `/icon_<id>` ([`TS3-NodeJS-Library/src/TeamSpeak.ts:2234-2241`](https://github.com/Multivit4min/TS3-NodeJS-Library/blob/0c69b7ee80fa5b74e9175cf4ae3018346f7eb300/src/TeamSpeak.ts#L2234-L2241))
 - TS3 PHP Framework: icon path uses `/icon_<unsigned id>` ([`ts3phpframework/src/Node/Node.php:137-146`](https://github.com/planetteamspeak/ts3phpframework/blob/87046b3d493c4d3d8064c639ea4269571192e476/src/Node/Node.php#L137-L146))
 - TS3 community forum: "The filename itself is the result of the CRC32 checksum" (TeamSpeak staff)
 ### 1.3 Implication for Cache Design
 Both avatars and icons are **content-addressed by the protocol itself**:
 | Asset | Content hash source | Same content across servers? |
 |---|---|---|
 | Avatar | `client_flag_avatar` = MD5 of bytes | Same bytes → same hash → same ID |
 | Icon | `icon_id` = CRC32 of bytes | Same bytes → same CRC32 → same ID |
 This means a **flat content-addressed blob store** can achieve zero-duplication without any per-server directories, hardlinks, or ref-counting.
 ---
 ## 2. Virtual Server Identity
 ### 2.1 Server UID
 | Aspect | Value |
 |---|---|
 | Protocol field | `virtualserver_unique_identifier` |
 | Type | `TYPE_STRING` (TeaSpeakLibrary `PropertyDefinition.h:22`) |
 | Generated by | The server instance, on creation |
 | Globally unique? | **Not guaranteed** — locally generated, no central registry |
 | Stable? | Yes — persists across restarts of the same virtual server |
 **Key fact:** `virtualserver_unique_identifier` is generated by each TS3 server. Two physically different servers could theoretically produce the same UID. It is **not safe as a global cache key**.
 ### 2.2 What Chanora Currently Tracks
 | Layer | Server identity fields | Source |
 |---|---|---|
 | Protocol adapter (`adapter.rs:1752-1755`) | `server_name`, `welcome_message`, `platform`, `version` | `state.server.*` from tsclientlib |
 | DTO (`ServerSnapshot`) | `server_name`, `welcome_message`, `platform`, `version` | No UID field |
 | Bridge (`BridgeSnapshot`) | Same as DTO | Same |
 | Storage (bookmarks) | Keyed by `host` (hostname:port) | SQLite `WHERE host = ?1` |
 | Core (recent servers) | `cfg.address` as host | Auto-saved on connect |
 **Chanora does not currently plumb `virtualserver_unique_identifier` through the DTO stack.** The field exists in tsclientlib's state but is not extracted.
 ### 2.3 Implication for Cache Design
 Using `virtualserver_unique_identifier` as the sole cache key is risky (not globally unique). Using connection address (`host:port`) is safe but duplicates cache entries when the same server is accessed via different addresses.
 **Recommendation:** For a content-addressed blob store, server identity is only needed for per-server metadata (eviction, "clear cache for this server"), not for the blob key itself. The blob key is the content hash.
 ---
 ## 3. Existing TS3 Client Cache Implementations
 ### 3.1 Qint (tsclientlib-based, Tauri + Rust)
 **Architecture:** Per-server directory with SQLite metadata.
 ```
 <cache>/files/<server-uid>/<channel-id>/<base64(path)>
 ```
 **Avatar handling:**
 - Avatar state stored per `(server, client)` row in SQLite
 - On avatar hash change, deletes the cached `/avatar_<uid>` file for that server
 - Avatar download path: `/avatar_<uid_base64>`
 **Icon handling:**
 - Icons path-cached with CRC32
 - Code comments note CRC32 collisions and freshness by mtime
 - Qint explicitly deletes and re-downloads when icon mtime changes
 **Dedup:** None. Same avatar on 5 servers = 5 stored copies.
 **Sources:**
 - [`Qint/proxy/src/filecache.rs`](https://github.com/ReSpeak/Qint/blob/7efe949adfa1a1ecb9d185e7740e015da18cc41b/proxy/src/filecache.rs#L1-L6): "Stores files transferred via the TS3 file transfer protocol. This includes icons and avatars."
 - [`Qint/proxy/src/db/mod.rs`](https://github.com/ReSpeak/Qint/blob/7efe949adfa1a1ecb9d185e7740e015da18cc41b/proxy/src/db/mod.rs#L1158-L1176): avatar hash change triggers delete
 - [`Qint/src-tauri/src/cmd.rs`](https://github.com/ReSpeak/Qint/blob/7efe949adfa1a1ecb9d185e7740e015da18cc41b/src-tauri/src/cmd.rs#L524-L539): file download command
 ### 3.2 TS3 Official Client (closed source)
 **Architecture:** Lazy cache with SDK callbacks.
 - `getAvatar()` returns cached path if present; otherwise triggers download
 - `onAvatarUpdated` callback fires when avatar is downloaded or deleted
 - Cache paths (from community documentation):
  - Windows: `%LOCALAPPDATA%\TeamSpeak\Cache\Default`
  - Linux: `~/.cache/TeamSpeak/Default`
  - macOS: `~/Library/Caches/TeamSpeak/Default`
 - SDK also exposes `CLIENT_MYTS_AVATAR` / `client_myteamspeak_avatar` for cross-server myTeamSpeak avatars
 **Sources:**
 - [`ts3client-pluginsdk/src/plugin.c`](https://github.com/teamspeak/ts3client-pluginsdk/blob/4aa90a53aa150cbf81e13bc97e68c0431b26499f/src/plugin.c#L384-L396): `getAvatar()` and `onAvatarUpdated`
 - [`ts3client-pluginsdk/public_rare_definitions.h`](https://github.com/teamspeak/ts3client-pluginsdk/blob/4aa90a53aa150cbf81e13bc97e68c0431b26499f/include/teamspeak/public_rare_definitions.h#L284-L313): `CLIENT_FLAG_AVATAR`, `CLIENT_MYTS_AVATAR`
 - Community: [clear cache](https://community.teamspeak.com/t/clear-cache/41511), [broken icons](https://community.teamspeak.com/t/server-icons-are-displaying-a-broken-image-issues-with-local-cache/58680)
 ### 3.3 TeaSpeak Client (TypeScript + C++ native)
 **Architecture:** Browser Cache API for images, per-server own-avatar storage.
 **Key components (from `.d.ts` type declarations):**
 - `AvatarManager` — per-connection (`FileManager`) avatar handler
  - `cachedAvatars` (private) — in-memory cache of `ClientAvatar` objects
  - `updateCache(clientAvatarId, clientAvatarHash)` — updates cache when hash changes
  - `resolveAvatar(clientAvatarId, avatarHash?, cacheOnly?)` — resolves avatar by ID
  - `flush_cache()` — clears cache
  - `create_avatar_download(client_avatar_id)` — initiates file transfer
 - `ClientAvatar` — tracks individual avatar state
  - `clientAvatarId` — derived from client UID via `uniqueId2AvatarId()`
  - `currentAvatarHash` — the `client_flag_avatar` value
  - State machine: `unset` → `loading` → `loaded` / `errored`
  - `loadingTimestamp` — when download started
 - `ImageCache` — generic image cache using browser Cache API
  - `resolveCached(key, maxAge?)` — check if cached
  - `putCache(key, value, type?, headers?)` — store
  - `cleanup(maxAge)` — evict old entries
  - `reset()` — clear all
  - `isPersistent()` — whether cache persists to disk
 - `OwnAvatarStorage` — user's own avatar, keyed by `serverUniqueId + mode`
  - `loadAvatarImage(serverUniqueId, mode)` — load own avatar for a server
  - `updateAvatar(serverUniqueId, mode, target)` — update own avatar
  - `avatarUploadSucceeded(serverUniqueId)` — move from "uploading" to "server" state
  - Stores `LocalAvatarInfo`: fileName, fileSize, **fileHashMD5**, timestamps, contentType
 - `FileManager` — per-connection file transfer manager
  - `MAX_CONCURRENT_TRANSFERS` — transfer concurrency limit
  - `avatars: AvatarManager` — avatar subsystem
  - `initializeFileDownload(options)` — start download (path, name, channel, target)
  - `deleteIcon(iconId: number)` — delete icon by ID
 - `FileTransfer` — transfer state machine
  - States: `PENDING → INITIALIZING → CONNECTING → RUNNING → FINISHED / ERRORED / CANCELED`
  - `InitializedTransferProperties`: serverTransferId, transferKey, **addresses[]**, protocol, seekOffset, fileSize
  - Multiple addresses returned by server for file transfer (failover)
 - `localIconCache: ImageCache` — global icon cache (singleton)
 **Sources:**
 - TeaSpeak-Client `imports/shared-app/file/Avatars.d.ts` — ClientAvatar, AbstractAvatarManager
 - TeaSpeak-Client `imports/shared-app/file/LocalAvatars.d.ts` — AvatarManager
 - TeaSpeak-Client `imports/shared-app/file/LocalIcons.d.ts` — localIconCache
 - TeaSpeak-Client `imports/shared-app/file/ImageCache.d.ts` — ImageCache (browser Cache API)
 - TeaSpeak-Client `imports/shared-app/file/FileManager.d.ts` — FileManager, transfer API
 - TeaSpeak-Client `imports/shared-app/file/Transfer.d.ts` — FileTransfer, state machine, error types
 - TeaSpeak-Client `imports/shared-app/file/OwnAvatarStorage.d.ts` — own avatar per-server storage
 - TeaSpeak-Client `native/serverconnection/test/js/ft.ts` — file transfer test (TCP + ftkey protocol)
 ### 3.4 TS3AudioBot (C#)
 **Architecture:** No local avatar cache. Avatar upload is hash-driven.
 - Uploads avatar bytes to `/avatar`, computes MD5, sets `client_flag_avatar` to that hash
 - Bot avatar selection reads local files from an `avatars/` directory
 - No caching of other users' avatars
 **Sources:**
 - [`TS3AudioBot/TSLib/TsBaseFunctions.cs:324-341`](https://github.com/Splamy/TS3AudioBot/blob/a69a38d8cba5a4d671dbe06505506f6b46f1d947/TSLib/TsBaseFunctions.cs#L324-L341)
 - [`TS3AudioBot/Bot.cs:420-470`](https://github.com/Splamy/TS3AudioBot/blob/a69a38d8cba5a4d671dbe06505506f6b46f1d947/TS3AudioBot/Bot.cs#L420-L470)
 ### 3.5 TS3 NodeJS Library
 **Architecture:** No local cache. Downloads on demand.
 - Avatar filename: `avatar_${clientBase64HashClientUID}`
 - `getAvatar()` downloads directly — no caching layer
 - Tests assert the exact `/avatar_<base64uid>` path
 **Sources:**
 - [`TS3-NodeJS-Library/src/node/Client.ts:300-313`](https://github.com/Multivit4min/TS3-NodeJS-Library/blob/0c69b7ee80fa5b74e9175cf4ae3018346f7eb300/src/node/Client.ts#L300-L313)
 - [`TS3-NodeJS-Library/tests/Client.spec.ts:342-358`](https://github.com/Multivit4min/TS3-NodeJS-Library/blob/0c69b7ee80fa5b74e9175cf4ae3018346f7eb300/tests/Client.spec.ts#L342-L358)
 ### 3.6 Summary Table
 | Client | Cache Key Strategy | Dedup Across Servers? | Icon Cache |
 |---|---|---|---|
 | **Qint** | `<server-uid>/<channel-id>/<path>` | No | Yes (CRC32, mtime freshness) |
 | **TS3 Official** | Lazy cache (path-based) | Unknown | Yes |
 | **TeaSpeak** | UID-derived avatar ID + browser Cache API | Implicit (same hash = same cache) | Yes (global ImageCache) |
 | **TS3AudioBot** | None | N/A | No |
 | **TS3 NodeLib** | None | N/A | No |
 | **Chanora (decided)** | Content hash (MD5/CRC32), flat `blobs/` in `chanora_cache` crate | **Yes** | Yes |
 ---
 ## 4. TeaSpeak Protocol Definitions (Authoritative)
 From TeaSpeakLibrary `src/PropertyDefinition.h` — the most complete open-source reference for TS3 protocol property types:
 ### 4.1 Avatar Properties
 ```cpp
 // Line 200
 PropertyDescription{CLIENT_FLAG_AVATAR, "client_flag_avatar", "",
    TYPE_STRING, FLAG_CLIENT_VIEW | FLAG_SAVE | FLAG_USER_EDITABLE}
 // "automatically up-to-date for any manager 'in view', this manager got an avatar"
 ```
 ### 4.2 Icon Properties
 ```cpp
 // Line 83 — server icon
 PropertyDescription{VIRTUALSERVER_ICON_ID, "virtualserver_icon_id", "0",
    TYPE_UNSIGNED_NUMBER, FLAG_SERVER_VVSS | FLAG_USER_EDITABLE}
 // Line 146 — channel icon
 PropertyDescription{CHANNEL_ICON_ID, "channel_icon_id", "0",
    TYPE_UNSIGNED_NUMBER, FLAG_CHANNEL_VIEW | FLAG_SS | FLAG_USER_EDITABLE}
 // Line 217 — client icon
 PropertyDescription{CLIENT_ICON_ID, "client_icon_id", "0",
    TYPE_UNSIGNED_NUMBER, FLAG_CLIENT_VIEW | FLAG_CLIENT_VARIABLE}
 ```
 ### 4.3 Server Identity
 ```cpp
 // Line 22
 PropertyDescription{VIRTUALSERVER_UNIQUE_IDENTIFIER,
    "virtualserver_unique_identifier", "",
    TYPE_STRING, FLAG_SERVER_VV | FLAG_SNAPSHOT}
 ```
 ### 4.4 File Transfer Permissions
 ```cpp
 // From PermissionManager.cpp
 PermissionType::i_client_max_avatar_filesize    // "Max avatar filesize in bytes"
 PermissionType::b_client_avatar_delete_other    // "Allow deletion of avatars from other clients"
 PermissionType::b_ft_transfer_list              // "Retrieve list of running filetransfers"
 ```
 ### 4.5 File Transfer Error Codes
 ```cpp
 // From Error.h
 channel_no_filetransfer_supported     = 0x30C
 file_transfer_connection_timeout      = 0x80E
 file_transfer_complete                = 0x811
 file_transfer_canceled                = 0x812
 file_transfer_interrupted             = 0x813
 file_transfer_server_quota_exceeded   = 0x814
 file_transfer_client_quota_exceeded   = 0x815
 file_transfer_reset                   = 0x816
 file_transfer_limit_reached           = 0x817
 ```
 ---
 ## 5. Cross-Platform Filesystem Research
 ### 5.1 Hardlink Support
 | Platform | Filesystem | Hardlinks in App-Private Storage? | Gotcha |
 |---|---|---|---|
 | Android (API 28+) | ext4 / f2fs | **Yes** | Rust uses `libc::link`; not FUSE-mounted; same-filesystem only |
 | iOS | APFS | **Yes** (writable sandbox dirs) | App bundle is read-only; avoid hardlinks to bundle assets |
 | macOS | APFS | **Yes** | — |
 | Linux | ext4 / btrfs / xfs | **Yes** | — |
 | Windows | NTFS | **Yes** | Rust uses `CreateHardLinkW` |
 **`std::fs::hard_link` gotchas (all platforms):**
 - Same filesystem required
 - Destination must not exist (returns error)
 - Symlink behavior is platform-specific
 - All hardlinks share the same inode — modifying one modifies all
 - Files must be treated as **immutable** for hardlink safety
 **Sources:**
 - Rust stdlib: `hard_link` maps to `libc::link` (Unix), `CreateHardLinkW` (Windows) ([Rust source](https://github.com/rust-lang/rust/blob/beae781308e9ddef13074a03faf57ca2fac59a5b/library/std/src/fs.rs#L2898-L2900))
 - Android: internal storage uses ext4/f2fs, not FUSE ([Android scoped storage docs](https://source.android.com/docs/core/storage/scoped))
 - iOS: APFS supports hardlinks; writable sandbox directories work ([Apple FileSystem basics](https://developer.apple.com/library/archive/documentation/FileManagement/Conceptual/FileSystemProgrammingGuide/FileSystemOverview/FileSystemOverview.html))
 ### 5.2 Rust Cache Libraries
 **`cacache`** (MIT licensed, production-ready):
 - Content-addressed disk cache
 - Automatic dedup, atomic writes, integrity verification
 - Exposes `hard_link`, `copy`, and `reflink` paths for retrieval
 - On-disk layout: `content-v2/sha512/...`
 - Could replace a custom implementation, but adds a dependency
 **Sources:**
 - [`cacache-rs` README](https://github.com/zkat/cacache-rs/blob/105692a4daa04ce5f5ef3f8688cd3e1c1fb6a7c0/README.md#L39-L60)
 - [`cacache-rs` content path](https://github.com/zkat/cacache-rs/blob/105692a4daa04ce5f5ef3f8688cd3e1c1fb6a7c0/src/content/path.rs#L6-L19)
 - [`cacache-rs` hard_link impl](https://github.com/zkat/cacache-rs/blob/105692a4daa04ce5f5ef3f8688cd3e1c1fb6a7c0/src/content/read.rs#L257-L285)
 ### 5.3 Flutter Cache Patterns
 Common Flutter packages use **cache-dir + metadata DB**, not hardlink dedup:
 - `flutter_cache_manager`: files in cache dir + `sqflite` metadata
 - `super_cache_disk`: file-per-entry (`.dat` + `.meta`) in app cache dir
 **Sources:**
 - [flutter_cache_manager on pub.dev](https://pub.dev/packages/flutter_cache_manager)
 - [super_cache_disk on pub.dev](https://pub.dev/packages/super_cache_disk/versions/1.0.0)
 ---
 ## 6. Chanora Codebase Context
 ### 6.1 Storage Patterns
 | Component | Pattern | Location |
 |---|---|---|
 | Identity storage | Atomic write (temp + `sync_all` + `rename`), mode 0600 on Unix | `chanora_storage/src/lib.rs:446-476` |
 | Metadata | Same atomic write pattern | `chanora_storage/src/lib.rs:480-515` |
 | Bookmarks | SQLite at `<storage_dir>/chanora.db`, keyed by `host` | `chanora_storage/src/lib.rs:782-928` |
 | Storage root | `getApplicationSupportDirectory()` from Flutter | `app_bootstrap.dart:19-24` |
 | Bridge init | `rust.initStorage(dir: dir)` | `app_bootstrap.dart:23-25,108-133` |
 ### 6.2 Existing Avatar Handling
 | Component | What | Location |
 |---|---|---|
 | UID to avatar path | `uid_to_avatar_path()` — base64 decode UID, encode each byte as 2 chars (a-p) | `adapter.rs:1561-1568` |
 | Client profile DTO | `avatar_path` field — set when `client.avatar_hash` and `unique_id` non-empty | `dto.rs:135-136`, `adapter.rs:1323-1332` |
 | No download | Currently no file download implementation exists | — |
 | No icon handling | No icon field/path in protocol DTO or adapter | — |
 ### 6.3 Server Identity in Chanora
 Chanora currently tracks servers by **connection address** (`host:port`), not by server UID:
 - Bookmarks: `WHERE host = ?1`
 - Recent servers: auto-saved by `cfg.address`
 - Prefetch cache: keyed by normalized host
 - ServerSnapshot: has `server_name` but no `server_uid`
 The `virtualserver_unique_identifier` field is available from tsclientlib's state but is **not extracted** by the adapter.
 ### 6.4 tsclientlib File Transfer API
 | Aspect | Detail |
 |---|---|
 | Download method | `Connection::download_file()` |
 | Stream items | `StreamItem::FileDownload(FileDownloadResult { size, stream })` |
 | Failure | `StreamItem::FiletransferFailed(handle, error)` |
 | TCP handling | tsclientlib handles TCP connection + ftkey writing automatically |
 | Chanora's job | Read `size` bytes from the returned `TcpStream` |
 | Async behavior | `StreamItem::FileDownload` fires asynchronously, not inline with the request |
 ### 6.5 ts-bookkeeping Generated Fields
 From the generated parser in `target/debug/build/ts-bookkeeping-*/out/`:
 - `virtual_server_id: u64` — numeric, per-virtual-server, may change across restarts
 - `virtual_server_uid` — string, the `virtualserver_unique_identifier`
 Both are available in the `InInitServer` struct from the init handshake but are not currently plumbed through.
 ---
 ## 7. TeaSpeak Server Internals (Authoritative)
 Source: TeaSpeak Server at `https://git.did.science/TeaSpeak/Server/Server` (branch `new-groups`, commit `b54c6d4e`).
 ### 7.1 Avatar ID Derivation — Server Side
 The server derives the avatar filename from the **client UID**, not from the avatar content:
 ```cpp
 // DataClient.cpp:242-244
 std::string DataClient::getAvatarId() {
    return hex::hex(base64::validate(this->getUid()) ? base64::decode(this->getUid()) : this->getUid(), 'a', 'q');
 }
 ```
 The same transform produces `client_base64HashClientUID` (shown to other clients):
 ```cpp
 // client.cpp:1113-1114
 bulk.put_unchecked("client_base64HashClientUID",
    hex::hex(base64::validate(info->client_unique_id) ? base64::decode(info->client_unique_id) : info->client_unique_id, 'a', 'q'));
 ```
 **This matches Chanora's existing `uid_to_avatar_path()` in `adapter.rs:1561-1568`.**
 ### 7.2 Avatar Upload Path
 When a client uploads an avatar, the server stores it as `/avatar_<avatarId>`:
 ```cpp
 // file.cpp:696-702
 } else if (cmd["path"].as<std::string>().empty() && cmd["name"].string() == "/avatar") {
    ...
    info.file_path = "/avatar_" + this->getAvatarId();
    transfer_response = file::server()->file_transfer().initialize_avatar_transfer(...);
 }
 ```
 The avatar file path is identity-based (from UID), not content-based.
 ### 7.3 `client_flag_avatar` — Who Computes the Hash?
 **The CLIENT computes the MD5 and sends it to the server during upload.** The server stores it as a string property (`FLAG_USER_EDITABLE`). The server does NOT compute or verify the hash.
 This means `client_flag_avatar` is:
 - Set by the uploading client
 - Stored verbatim by the server
 - Broadcast to other clients as part of the client properties
 - A reliable content fingerprint: same avatar bytes → same MD5 → same `client_flag_avatar` on any server
 ### 7.4 Icon IDs — Server Does NOT Compute CRC32
 Icon IDs are **permission values**, not content hashes computed by the server:
 ```cpp
 // ConnectedClient.cpp:186-210 — client icon ID from permissions
 auto permission_flags = local_permissions->permission_flags(permission::i_icon_id);
 new_icon_id = value.value;
 updated_client_properties.emplace_back(property::CLIENT_ICON_ID);
 ```
 ```cpp
 // channel.cpp:1495-1504 — channel icon ID
 if(key == property::CHANNEL_ICON_ID) {
    auto icon_id = converter<uint32_t>::from_string_view(value);
    channel->permissions()->set_permission(permission::i_icon_id, { ... icon_id ... });
 }
 ```
 ```cpp
 // server.cpp:76-89 — server icon ID
 SERVEREDIT_CHK_PROP_CACHED("virtualserver_icon_id", permission::b_virtualserver_modify_icon_id, int64_t)
 ```
 **The CLIENT computes the CRC32 during upload and uses it as the filename `/icon_<crc32>`.** The server stores the file and records the ID as a permission value. No server-side CRC32 or MD5 computation exists.
 ### 7.5 Per-Server Storage Layout
 Avatars and icons are stored **per virtual server** on the server's filesystem:
 ```cpp
 // LocalFileSystem.cpp:39-45
 fs::path LocalFileSystem::server_path(const std::shared_ptr<VirtualFileServer> &server) {
    return fs::u8path(this->root_path_) / fs::u8path("server_" + std::to_string(server->server_id()));
 }
 // target_path = this->server_path(server) / "icons" / path;
 // target_path = this->server_path(server) / "avatars" / path;
 ```
 ```
 <server_root>/
  server_<sid>/
    avatars/
      /avatar_<avatarId>     ← one per client who uploaded
    icons/
      /icon_<id>             ← one per unique icon
 ```
 ### 7.6 File Transfer Protocol (Server Side)
 Upload/delete/query routing:
 ```cpp
 // file.cpp:273-341 — delete routing
 if (first_entry_name.find("/icon_") == 0 && file_path.empty()) { ... delete_icons(...); }
 else if (first_entry_name.starts_with("/avatar_") && file_path.empty()) { ... delete_avatars(...); }
 ```
 ```cpp
 // file.cpp:483-523 — query routing
 if (first_entry_name.find("/icon_") == 0 && file_path.empty()) { ... query_icon_info(...); }
 else if (first_entry_name.starts_with("/avatar_") && file_path.empty()) { ... query_avatar_info(...); }
 ```
 Transfer initialization returns ftkey and metadata:
 ```cpp
 // file.cpp:759-761
 result.put_unchecked(0, "ftkey", transfer->transfer_key);
 result.put_unchecked(0, "seekpos", transfer->file_offset);
 ```
 ```cpp
 // file.cpp:887-899
 result.put_unchecked(0, "ftkey", transfer->transfer_key);
 result.put_unchecked(0, "proto", "1");
 result.put_unchecked(0, "size", transfer->expected_file_size);
 ```
 ### 7.7 Key Takeaway for Chanora
 | Who does what | Avatar | Icon |
 |---|---|---|
 | **Uploader (client)** computes | MD5 of avatar bytes → sets `client_flag_avatar` | CRC32 of icon bytes → filename `/icon_<crc32>` |
 | **Server** does | Stores file as `/avatar_<uid>`, saves property | Stores file as `/icon_<id>`, saves permission |
 | **Other clients** receive | `client_flag_avatar` (MD5) as a property update | `icon_id` (CRC32) as a property update |
 | **Chanora cache key** | `av_<md5>.dat` — content fingerprint | `ic_<crc32>.dat` — content fingerprint |
 The content hash is computed once (by the uploader) and then broadcast as a property. Chanora never needs to hash anything — it just uses the protocol-provided values as cache keys.
 ---
 ## 8. Design Implications
 ### 8.1 The Core Insight
 The TS3 protocol provides content hashes as part of normal server-to-client updates:
 | Event | Data provided by server | What Chanora gets for free |
 |---|---|---|
 | Client enters view | `client_flag_avatar` = MD5 of avatar bytes | Content key for blob store |
 | Channel update | `channel_icon_id` = CRC32 of icon bytes | Content key for blob store |
 | Server update | `virtualserver_icon_id` = CRC32 of icon bytes | Content key for blob store |
 No hashing needed on the client side. The protocol is **already content-addressed**.
 ### 8.2 Recommended Cache Architecture
 ```
 <app_cache_dir>/chanora/
  blobs/                         ← cacache content store root
    content-v2/                  ← content-addressed by SHA-512
      <sha512-hex>/data          ← raw blob bytes
    index-v2/                    ← key → content mapping
 ```
 Where `<app_cache_dir>` is the platform cache directory (not the support directory used by `chanora_storage`). Chanora's `BlobCache` maps protocol keys (`av_<md5>`, `ic_<crc32>`) to `cacache` string keys. Physical layout is managed by `cacache`.
 **Lookup flow:**
 1. Server sends `client_flag_avatar = "a1b2c3d4..."` for user X
 2. Check: does `blobs/av_a1b2c3d4....dat` exist?
 3. Yes → use it, zero downloads (works for ANY server)
 4. No → download from `/avatar_<uid_base64>` → save as `blobs/av_a1b2c3d4....dat`
 **Same for icons with `ic_<crc32>.dat`.**
 ### 8.3 Why This Beats Alternatives
 | Approach | Dedup | Globally unique key | Needs server UID plumbing | Needs hardlinks | Complexity |
 |---|---|---|---|---|---|
 | `<server_uid>/<hash>.dat` | No | No (UID not guaranteed unique) | Yes | Optional | Medium |
 | `<host>_<port>/<hash>.dat` | No | Yes | No | Optional | Medium |
 | `<host>_<port>/<hash>.dat` + hardlinks | Yes | Yes | No | Yes | Medium-High |
 | **`blobs/av_<hash>.dat` (flat)** | **Yes** | **Yes (content hash)** | **No** | **No** | **Low** |
 ### 8.4 Trade-offs
 | Pro | Con |
 |---|---|
 | Zero duplication across all servers | "Clear cache for server X only" requires metadata layer (Phase 3+) |
 | No hardlinks needed | Orphan cleanup requires scanning for unreferenced blobs |
 | No server UID plumbing needed | Cannot distinguish same-hash-different-content for icons (CRC32 collision) |
 | Simplest possible implementation | — |
 | Freshness = hash change = different filename (automatic) | — |
 | Cross-platform (just file I/O) | — |
 ### 8.5 Phased Implementation
 | Phase | What | Delivers |
 |---|---|---|
 | 1 | Protocol download (raw bytes via adapter, no cache) | Working download pipeline |
 | 2 | Bridge + Flutter display (`Image.memory()`) | Visible avatars in UI |
 | 3 | `chanora_cache` crate: cacache-backed blob cache, separate crate, cache dir, mtime eviction | Zero re-downloads, zero duplication |
 | 4 | Session orchestration (coalescing, rate limiting, negative cache) | Anti-flood, robustness |
 | 5 | Cache management (clear all, orphan cleanup, optional per-server metadata) | User control |
 ---
 ## 9. Resolved Questions
 ### Q1: Icon CRC32 Collisions — Accept with Size Guard
 **Risk assessment:** CRC32 produces a 32-bit hash. For N unique icons, the Birthday paradox gives collision probability ≈ N² / (2 × 2³²).
 | Icons (N) | Collision probability |
 |---|---|
 | 100 | ~0.0001% (negligible) |
 | 1,000 | ~0.01% (negligible) |
 | 10,000 | ~1.2% (marginal) |
 | 65,536 | ~50% (likely) |
 A single user typically encounters fewer than 1,000 unique icons across all servers. The practical collision risk is negligible.
 **What happens on collision:** Wrong icon displayed for a channel/client/server. This is a visual glitch, not a security issue. The icon will appear incorrect until the cache is cleared.
 **Existing practice:** Qint explicitly notes CRC32 collisions (`filecache.rs:4`) but does NOT guard against them — they only refresh icons by mtime. No other TS3 client guards against CRC32 collisions.
 **Recommendation:** Accept CRC32 as the cache key. Add a lightweight **file size guard**: when downloading an icon, if `ic_<crc32>.dat` already exists but has a different size than the `ftinitdownload` response reported, re-download. File size is available from the protocol (`msg.size` in `InFileDownloadPart`). This catches most collisions (different content = different size with high probability) without computing a secondary hash.
 **Decision:** CRC32 + file size guard. No SHA256 overhead needed.
 ---
 ### Q2: `client_myteamspeak_avatar` — Defer Indefinitely
 **What it is:** A string property (`Option<String>` in ts-bookkeeping) broadcast alongside `client_flag_avatar`. It represents a myTeamSpeak cross-server avatar — a user linked to a myTeamSpeak account can set a global avatar that follows them across all servers.
 **Current state in Chanora's dependency chain:**
 - ts-bookkeeping exposes it: `InInitServer` has `my_team_speak_avatar: Option<String>`
 - TeaSpeakLibrary tracks `client_myteamspeak_id` but not the avatar
 - tsclientlib exposes it as a property on client state
 **Value for Chanora:**
 - myTeamSpeak is a TeamSpeak-specific cloud service (account sync, cross-server features)
 - Chanora is an independent client — no myTeamSpeak account integration is planned
 - The property may contain a URL or identifier that requires myTeamSpeak API access to resolve
 - Without myTeamSpeak integration, the avatar cannot be fetched
 **Recommendation:** Defer indefinitely. If Chanora ever integrates myTeamSpeak accounts, this can be handled as a separate avatar source (URL-based HTTP download) alongside the existing protocol-based avatar download. The cache architecture supports this — just add a different blob prefix (e.g., `mt_<hash>.dat`).
 **Decision:** Out of scope for MVP and foreseeable roadmap.
 ---
 ### Q3: Cache Backing Store — `cacache` Wrapper in Separate `chanora_cache` Crate
 **Decision:** Use `cacache` as the backing store inside `chanora_cache`. Not a custom flat-file implementation.
 **Why cacache won over custom:**
 1. **Crash safety is production-tested.** `cacache` handles partial writes, power loss, crash mid-write. A custom implementation would need to get `sync_all` + atomic rename right — one bug = corrupted cache. Even though cache data is disposable (reconstructible from server), `cacache` eliminates this entire class of bugs.
 2. **Less code to maintain.** ~120 LOC wrapper vs ~200 LOC custom implementation. The hard parts (atomic writes, integrity, content dedup) are owned by `cacache`, tested by the npm ecosystem.
 3. **Integrity verification on every read.** SSRI verification detects corruption, bit rot, partial writes automatically. A custom impl would need to add this separately or accept silent corruption.
 4. **Content dedup by SHA-512.** Same avatar on two servers = stored once automatically. The protocol's MD5/CRC32 keys map to `cacache` string keys; content dedup happens at the SHA-512 layer underneath.
 **What about the downsides:**
 | Concern | Assessment |
 |---|---|
 | ~6 transitive deps | `sha2` already in tree via `chacha20poly1305`. `serde_json`, `tempfile`, `digest` are lightweight. Acceptable for the safety benefit. |
 | SHA-512 overhead on every write/read | For <100KB avatars, SHA-512 takes ~0.1ms. Negligible. |
 | Opaque on-disk format | `cacache` provides `ls()` API for enumeration and inspection. Not as simple as `ls blobs/` but adequate. |
 | `cacache` has no built-in LRU eviction | We write a custom eviction pass using `cacache::ls()` + timestamp sort. ~20 lines. Same complexity as custom impl's eviction. |
 **Separate crate rationale:**
 - `chanora_cache` is separate from `chanora_storage` because cache data has different durability semantics (disposable vs persistent), different backup semantics (excluded vs included), and different directory placement (cache dir vs support dir).
 - `chanora_cache` lives in the platform's cache directory (`getApplicationCacheDirectory()`). `chanora_storage` lives in the support directory (`getApplicationSupportDirectory()`).
 - Bridge init is separate: `init_cache(cache_dir)` vs `init_storage(support_dir)`.
 **API design:**
 ```rust
 pub struct BlobCache { cache_dir: PathBuf, max_bytes: u64 }
 impl BlobCache {
    pub fn new(cache_dir: impl AsRef<Path>, max_bytes: u64) -> Result<Self, BlobCacheError>;
    pub async fn put(&self, prefix: &str, key: &str, data: &[u8]) -> Result<(), BlobCacheError>;
    pub async fn get(&self, prefix: &str, key: &str) -> Result<Option<Vec<u8>>, BlobCacheError>;
    pub async fn remove(&self, prefix: &str, key: &str) -> Result<(), BlobCacheError>;
    pub async fn clear(&self) -> Result<(), BlobCacheError>;
    pub async fn total_size(&self) -> Result<u64, BlobCacheError>;
    pub async fn evict(&self) -> Result<(), BlobCacheError>;
 }
 ```
 All methods are async (cacache is async-native). Key validation at API boundary (`av_` = 32 hex chars, `ic_` = decimal digits).
 ---
 ### Q4: Per-Blob Metadata — No Metadata Sidecars (Resolved)
 **Original options:**
 | Approach | Pros | Cons |
 |---|---|---|
 | SQLite (chanora.db) | ACID, queryable, already in use | Schema migration, couples cache to bookmark DB |
 | JSON sidecar files | Simple, self-contained, easy to debug | Write amplification (2 files per blob), concurrent write risk |
 | In-memory only | Simplest | Lost on restart, can't do orphan cleanup offline |
 | **No metadata (mtime-based)** | **Simplest, zero write amplification, 1 file per blob** | **No per-blob metadata beyond mtime** |
 **Why no metadata is sufficient:**
 1. **Content is immutable.** A given hash (MD5 or CRC32) always maps to the same bytes. There is no "stale content" problem — if the hash changes, it's a new file with a new name. No invalidation needed.
 2. **mtime = insertion time.** Since content is never modified after write, the filesystem mtime equals the time the blob was cached. This is sufficient for "delete oldest files first" eviction.
 3. **Write amplification avoided.** One file per blob (just the data) instead of two (data + JSON sidecar). For a cache that may hold thousands of small files, this matters.
 4. **Eviction is simple.** `walk dir → stat → sort by mtime → delete oldest`. No JSON parsing, no schema, no migration.
 5. **Per-server metadata deferred.** "Clear cache for server X only" and orphan cleanup are post-MVP features. If needed, a refs-layer can be added later without changing the blob layout.
 **Oracle consultation:** Oracle recommended this approach explicitly — no metadata files, mtime-based eviction, separate crate. The immutability guarantee makes metadata redundant.
 **Decision:** No metadata sidecars. One file per blob. Mtime-based eviction. Per-server metadata deferred to post-MVP.
 ---
 ### Q5: File Transfer Address Failover — Not Needed
 **What the protocol provides:**
 The TeaSpeak client's `InitializedTransferProperties` returns `addresses[]` — an array of `{serverAddress, serverPort}`. The official TS3 client can try multiple addresses for failover.
 **What tsclientlib provides:**
 ```rust
 // tsclientlib/src/lib.rs:1373-1375
 let ip = msg.ip.unwrap_or_else(|| self.client.address.ip());
 let addr = SocketAddr::new(ip, msg.port);
 TcpStream::connect(&addr).await
 ```
 tsclientlib's `InFileDownloadPart` has `ip: Option<IpAddr>` — **single IP only**, not an array. If the server provides an IP, it uses that. Otherwise, it falls back to the connection address. **No multi-address failover.**
 **What ts-bookkeeping parses:**
 ```rust
 pub struct InFileDownloadPart {
    pub client_filetransfer_id: u16,
    pub server_filetransfer_id: u16,
    pub filetransfer_key: String,
    pub port: u16,
    pub size: u64,
    pub protocol: u8,
    pub ip: Option<IpAddr>,    // ← single optional IP
 }
 ```
 **The server's `notifystartdownload` response** sends `ip` as an optional single value, not an array. The TeaSpeak client's `addresses[]` is a higher-level abstraction (likely the client's own fallback logic), not a protocol feature.
 **Recommendation:** Chanora follows tsclientlib's existing behavior — use `msg.ip` or fallback to connection address. No custom failover logic needed. If the TCP connection fails, the download fails and retries follow the exponential backoff strategy from the design doc.
 **Decision:** Single address (from tsclientlib). No failover needed.
Author	SHA1	Message	Date
Edison Jwa	4faaabb5b3	fix(core,protocol): simplify store_protocol and add download size cap - store_protocol: always write to shared Arc<Mutex<Option<ProtocolClient>>>; the FileTransferService holds the same Arc so it sees updates automatically - read_download_bytes: reject downloads exceeding 10 MB to prevent malicious servers from causing OOM	2026-06-10 09:36:27 +09:00
Edison Jwa	f0e1621fdf	feat(core,bridge): add get_icon with coalescing and negative cache - FileTransferService::get_icon() mirrors get_avatar pattern - ChanoraSession::get_icon() delegates through FileTransferService - Bridge download_icon() exposed for Flutter - Dart downloadIcon() shim added - Uses PREFIX_ICON (ic_<crc32u>) cache key format - 1 new unit test (cached icon hit)	2026-06-10 07:38:21 +09:00
Edison Jwa	82ea1a117f	feat(core): FileTransferService with coalescing, throttling, negative cache - New file_transfer module with FileTransferService struct - Semaphore(2) throttles concurrent downloads - In-flight HashMap coalesces duplicate avatar requests - 5-min negative cache short-circuits ServerRejected misses - ChanoraSession delegates get_avatar through the service - connect/disconnect update shared protocol handle - clear_cache/cache_size delegate to service - 2 new unit tests (cached hit, negative cache)	2026-06-10 07:24:08 +09:00
Edison Jwa	8ffd33b3cc	feat(flutter): add cache initialization wiring and avatar download shims - Add wireCache() to app_bootstrap using getApplicationCacheDirectory() - Call wireCache() after wireStorage() in main bootstrap flow - Add Dart-side initCache and downloadAvatar wrapper shims in api.dart - Update Cargo.lock for new chanora_cache dependency	2026-06-10 07:09:55 +09:00
Edison Jwa	1fa9940e88	feat(bridge): add init_cache, download_avatar, and cache management functions - Add init_cache(dir) bridge function - Add download_avatar(avatar_hash, client_uid) bridge function - Add clear_file_cache() and file_cache_size() bridge functions - Map CoreError::Cache and ProtocolError::FileTransfer in BridgeError	2026-06-10 07:09:47 +09:00
Edison Jwa	8c6538aa41	feat(core): add blob cache wiring and avatar download orchestration - Add chanora_cache dependency to Cargo.toml - Add blob_cache field to ChanoraSession (Arc<Mutex<Option<BlobCache>>>) - Add init_cache() method: creates BlobCache, runs eviction - Add get_avatar() method: cache-first, download on miss, store in cache - Add clear_cache() and cache_size() methods for cache management - Add CoreError::Cache variant for BlobCacheError conversion - Add avatar_cache integration test	2026-06-10 07:09:40 +09:00
Edison Jwa	6c380fc7db	feat(protocol): add file download support for avatars and icons - Add Request::DownloadFile variant with oneshot reply - Add ProtocolClient::download_avatar(client_uid) and download_icon(icon_id) - Track pending file downloads by FiletransferHandle - Handle StreamItem::FileDownload: read bytes from TCP stream - Handle StreamItem::FiletransferFailed: map to ProtocolError - Add ProtocolError::FileTransfer(String) variant - Add path helper tests for avatar/icon download paths - No tsclientlib types leak across the adapter boundary	2026-06-10 04:49:12 +09:00
Edison Jwa	21fd979560	feat(cache): add chanora_cache crate with cacache-backed blob cache - New chanora_cache crate: content-addressed blob store wrapping cacache - BlobCache API: async put/get/remove/clear/total_size/evict - Key validation: av_ prefix (32 hex chars), ic_ prefix (decimal digits) - Cacache provides crash safety, SSRI integrity, content dedup - Mtime-based eviction via cacache::list_sync + sort by timestamp - 7 unit tests all passing - Added to workspace members	2026-06-10 04:36:59 +09:00
Edison Jwa	021c39e95c	docs(architecture): add file transfer design, research, and implementation plan	2026-06-10 04:28:58 +09:00