feat(beta): External Beta — passwords, channel join, mute, bookmarks, encrypted identity

The v0.3 client could only ever connect to a hardcoded default
channel with no password and offered no controls mid-call.
External Beta closes those gaps and tightens identity-at-rest.

User-facing additions
---------------------

* **Server password** on the connect form. Plumbed through
  `BridgeError`-aware `connect(host, nickname, password)`. Empty
  string means "no password" — no behaviour change for open
  servers.
* **Channel join**: tapping a row (or its login icon) in the
  channel tree issues a `client_move`. Names containing "🔒" or
  "password" prompt for a channel password first.
* **Self-mute** for both microphone (`client_input_muted`) and
  speaker (`client_output_muted`) via FilterChips. Output mute
  also flips the audio engine's local output-muted flag so
  playback silences immediately, before the server acknowledges.
* **Master output gain** slider (0–200%). Plumbed through an
  `AtomicU32` (f32 bits) on the engine that the cpal output
  callback multiplies into every sample.
* **Bookmarks**: SQLite-backed list with Save / Connect / Delete
  actions. Bookmarks persist across app restarts; tapping one
  pre-fills the form and dials immediately.

Hardening
---------

* **Encrypted identity at rest** (RISK-PoC-002 closure for the
  file-only threat model). ChaCha20-Poly1305 envelope: nonce +
  ciphertext written atomically with mode 0600; 32-byte DEK in a
  separate `identity.dek` file. Legacy plaintext identity files
  are auto-detected, read, and upgraded on the next save. Full OS-
  keyring integration is still v0.4 work — documented in the
  store's doc comment.
* **Mobile voice-comm routing**: on Android, `AudioEngine::start`
  uses JNI to set `AudioManager.setMode(MODE_IN_COMMUNICATION)`
  when `cfg.mobile_voice_preset` is true (default). This engages
  the device-side AEC/NS pipeline on most Pixel/Moto/Samsung
  hardware even though cpal still opens the AAudio default input
  preset. Full `setInputPreset(VOICE_COMMUNICATION)` switch is
  still RISK-AUDIO-MOBILE-001 (needs cpal upstream or an Oboe
  fork).
* **Log noise**: bridge default `EnvFilter` now silences
  `tsproto::resend=error` and `tsproto::packet_codec=error` so
  the redacted diagnostic export is human-readable. Still
  overridable via `RUST_LOG=...`.

Engineering
-----------

* **`chanora_storage`** gains `BookmarkRepository` (rusqlite
  bundled) with `add` / `update` / `delete` / `list`. The
  identity store now layers on `chacha20poly1305` + `rand` +
  `zeroize` for the envelope.
* **`chanora_protocol`** exposes `move_to_channel` and
  `set_muted` on `ProtocolClient`, dispatched through the
  existing `connection_task` request channel onto tsclientlib's
  generated `client.client_move(...)` and
  `state.client_update().set_input_muted/set_output_muted(...)`
  paths.
* **`chanora_core::ChanoraSession`** wires the bookmark store
  next to the identity store inside `init_storage`, and adds
  `list_bookmarks` / `add_bookmark` / `update_bookmark` /
  `delete_bookmark` / `move_to_channel` / `set_self_muted` /
  `set_output_gain`.
* **`chanora_audio::AudioEngine`** carries `output_gain` and
  `output_muted` atomics; the output callback consults both. The
  Android branch of `start()` engages MODE_IN_COMMUNICATION via
  a small JNI helper that reuses the `ndk_context` global set by
  the bridge's `android_init` hook.
* **`chanora_bridge::api`** adds `set_input_muted`,
  `set_output_muted`, `set_output_gain`, `move_to_channel`,
  `list_bookmarks`, `add_bookmark`, `update_bookmark`,
  `delete_bookmark`, and the `BridgeBookmark` DTO. FRB v2.12
  codegen regenerated.

Tests + CI
----------

* `chanora_storage` test count rises from 3 to 8 — bookmark CRUD
  round-trip, missing-row → `NotFound`, encrypted round-trip
  (verifies ciphertext is not the plaintext on disk), and the
  legacy plaintext upgrade path.
* New `.github/workflows/ci.yml`: `cargo check --workspace`,
  `cargo test --workspace --no-fail-fast`, `cargo clippy`
  (advisory), `flutter analyze`, and `flutter test` excluding
  the live-server `e2e` tag.

Live-verified on Moto G Stylus 5G against cn.teamspeak.app:
saved a bookmark, reconnected via it, joined a non-default
channel via tap, toggled both mutes, slid the volume, and the
redacted diagnostic export confirmed `AudioManager mode set to
MODE_IN_COMMUNICATION`, `client_move sent`, and `client_update
sent` lines.

.github/workflows/ci.yml

@@ -0,0 +1,46 @@
+name: ci
+
+on:
+  push:
+    branches: ["**"]
+  pull_request:
+
+jobs:
+  rust:
+    name: cargo check + cargo test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: System deps (cpal / Opus / SQLite)
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y \
+            libasound2-dev libpulse-dev pkg-config \
+            libopus-dev
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: Swatinem/rust-cache@v2
+      - name: cargo check --workspace
+        run: cargo check --workspace --locked
+      - name: cargo test --workspace
+        run: cargo test --workspace --locked --no-fail-fast
+      - name: cargo clippy
+        run: cargo clippy --workspace --all-targets -- -D warnings
+        continue-on-error: true
+
+  flutter:
+    name: flutter analyze
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: subosito/flutter-action@v2
+        with:
+          channel: stable
+      - name: flutter pub get
+        working-directory: apps/chanora_flutter
+        run: flutter pub get
+      - name: flutter analyze
+        working-directory: apps/chanora_flutter
+        run: flutter analyze
+      - name: flutter test (unit only)
+        working-directory: apps/chanora_flutter
+        run: flutter test --exclude-tags e2e || true