docs: add README files to 9 crates and update verification plan (TODO-030,036)

Add purpose, architecture, and public API summary to each crate
README following chanora_resolver pattern. Update verification master
plan with new evidence sources and entry/exit criteria.

core/chanora_core/README.md

@@ -0,0 +1,74 @@
+# chanora_core
+
+Top-level Rust API and orchestration layer for the Chanora client. Composes subsystem crates behind a stable, typed API consumed by `chanora_bridge`. Owns no protocol, audio, or storage logic directly.
+
+## Architecture
+
+Per SAD §7.2, `chanora_core` is the integration point:
+
+- **`ChanoraSession`** — the primary public type. Owns at most one active server connection (DEC-006). Provides connect, disconnect, snapshot, audio lifecycle, PTT, bookmarks, and diagnostics methods.
+- **Supervisor** — a per-connection tokio task that monitors connection health via a loss notifier and a watchdog probe, and auto-reconnects with exponential backoff (1 s → 60 s capped). Re-attaches the audio engine if it was running prior to the loss.
+- **`SessionEvent`** — broadcast enum emitted on connect/lost/reconnecting/disconnected/audio-started/audio-stopped/voice-state/chat/route changes. Subscribers consume via `subscribe_events()`.
+- **File transfer** — avatar/icon download routed through a cacache-backed blob cache with LRU eviction.
+- **Channel join state machine** — reducer-based state tracking for voice channel joins, with optimistic commands, snapshot reconciliation, and error projection.
+- **PTT controller** — platform input backend management, binding persistence, and release-tail timer wiring (SDD-088/094/096).
+
+## Public API Summary
+
+### Core types
+
+| Type | Role |
+|---|---|
+| `ChanoraSession` | Top-level session handle; cloneable, thread-safe |
+| `CoreError` | Unified error enum covering all subsystem errors |
+| `SessionEvent` | Broadcast lifecycle event enum |
+| `ConnectConfig` | Typed connection parameters |
+| `NetworkState` | OS connectivity state enum |
+
+### Key methods on `ChanoraSession`
+
+- `new()` — construct an empty session (no I/O)
+- `init_storage(dir)` — wire identity + bookmark stores
+- `init_cache(dir)` — wire the blob cache for avatars/icons
+- `connect(cfg)` → `ServerSnapshot` — dial a server (single-connection invariant)
+- `disconnect()` — clean teardown including supervisor
+- `is_connected()` — check connection state
+- `snapshot()` → `ServerSnapshot` — refresh server state
+- `client_profile(client_id)` — rich profile for one client
+- `voice_join(channel_id, password)` / `voice_leave()` — audio lifecycle
+- `start_audio(cfg)` — initialize audio subsystem
+- `set_input_device(id)` / `set_output_device(id)` — device selection
+- `set_output_gain(gain)` / `set_client_volume(client_id, volume)` — volume control
+- `set_transmit_mode(mode)` / `get_transmit_mode()` — transmit mode
+- `set_hard_mute(muted)` — hard-mute clamp
+- `set_release_tail_ms(ms)` / `get_release_tail_ms()` — release-tail config
+- `set_ptt(active)` / `set_ptt_binding(binding)` / `ptt_descriptor()` — PTT control
+- `send_text_message(message, target)` — chat
+- `move_to_channel(id, password)` / `set_self_muted(input, output)` — channel + mute
+- `subscribe_events()` — broadcast receiver for `SessionEvent`
+- `drain_protocol_events()` / `protocol_events_snapshot()` — protocol event access
+- `export_diagnostics()` — redacted diagnostic bundle (includes network stats)
+- `audio_stats()` — audio subsystem telemetry
+- `network_diagnostics_summary()` — network statistics
+- `prefetch_server(host)` — warm server-address resolution
+- `set_audio_processing_config(cfg)` / `get_audio_processing_config()` — audio DSP config
+- `set_audio_debug_wav_dump(enabled)` — WAV dump toggle
+- `set_vad_model_path(path)` — Silero model path
+- `transmit_selector()` / `release_tail_timer()` — subsystem accessors
+
+### Re-exports
+
+Re-exports selected types from `chanora_protocol`, `chanora_audio`, `chanora_storage`, and `chanora_diagnostics` so the bridge only depends on `chanora_core`.
+
+## Platform notes
+
+- iOS/macOS-specific methods (`ios_handle_route_change`, `ios_handle_interruption_began`, etc.) are gated behind `cfg(target_os = "ios" | "macos")` inside method bodies.
+- Android-specific reconnect paths are similarly gated.
+- The crate itself compiles on all targets; platform-specific code is runtime- or cfg-gated.
+
+## Invariants
+
+- Single active connection at runtime (DEC-006)
+- `tsclientlib` types never cross out of `chanora_protocol` (SAD-067)
+- Secret material never lands in non-secret storage (DEC-013.2)
+- Audio engine construction failure preserves the previous engine state