feat(alpha): wire connect→snapshot→disconnect end-to-end (v0.1.0-alpha.1)

First Internal Alpha build per DEC-001. Closes the milestone of
'Flutter UI calls Rust via the typed bridge, Rust connects to a
TeamSpeak-compatible server through tsclientlib, returns a typed
snapshot, and disconnects cleanly.' Audio remains Beta scope.

Promotions from PoC:
  poc/tsclientlib-connect-spike  →  crates/chanora_protocol/

New product code:
  crates/chanora_protocol/src/{dto.rs,adapter.rs} — typed boundary
    over tsclientlib. Tokio task owns the Connection; public
    handle communicates via mpsc/oneshot. No tsclientlib types
    cross out of the crate (SAD-067 / SysDes-011 / SysDes-029).
  core/chanora_core/src/lib.rs — ChanoraSession composes the
    protocol crate, enforces the DEC-006 single-connection
    invariant.
  crates/chanora_bridge/src/{api.rs,frb_generated.rs} — FRB 2.12.0
    bridge per DEC-014. cdylib + staticlib + rlib. Typed
    BridgeSnapshot / BridgeChannel / BridgeClient / BridgeError
    DTOs. Process-wide OnceLock<Runtime> + OnceLock<ChanoraSession>.
  flutter_rust_bridge.yaml at repo root.
  apps/chanora_flutter/lib/main.dart — Alpha UI: server form,
    connect button, channel tree, disconnect.
  apps/chanora_flutter/lib/l10n/app_{en,zh}.arb expanded with the
    Alpha key set; ARB metadata reaffirms ADR-008 for
    server-provided content.
  Generated Dart bindings under apps/chanora_flutter/lib/src/rust/.

Empirical verification (2026-05-14):
  Workspace: cargo check + cargo test clean
    (workspace tests: all green).
  Bridge cdylib: target/release/libchanora_bridge.so produced
    (~15 MB).
  Flutter: flutter analyze clean; flutter test runs 3/3 green
    including the alpha_e2e_test that drives the full
      Dart → FRB → chanora_bridge → chanora_core → chanora_protocol
        → tsclientlib → UDP → cn.teamspeak.app
    path. The captured logcat/stdout shows the tsproto resender
    transitioning Connected → Disconnecting → Disconnected on
    clean teardown.

Architecture changes:
  - Removed the chanora_core ↔ chanora_bridge cyclic dependency.
    chanora_core no longer knows the bridge exists; the bridge
    maps from CoreError.
  - chanora_bridge crate's #![forbid(unsafe_code)] lint relaxed
    because FRB-generated glue legitimately uses unsafe at the
    FFI boundary. Hand-written code remains unsafe-free.

Open follow-ups (NOT in this Alpha):
  - Audio capture/playback wiring into chanora_audio
    (Beta scope per DEC-001).
  - Identity persistence via chanora_storage
    (currently regenerated on every connect).
  - Per-message diagnostics + redaction
    (chanora_diagnostics still scaffold).
  - Reconnect / network-loss recovery.
  - Mobile (Android) build of the bridge cdylib + UI verification.

crates/chanora_protocol/src/lib.rs

@@ -4,48 +4,66 @@
 //! behind a typed boundary so the rest of Chanora is decoupled from
 //! the upstream library's types (SAD-067, SysDes-011, SysDes-029).
 //!
-//! ## Status
+//! ## What this crate exposes
 //!
-//! Scaffold only. Promotion of `poc/tsclientlib-connect-spike` into
-//! this crate happens later, with its own audit-trail commit.
+//! * [`ConnectConfig`] — typed connection parameters.
+//! * [`ProtocolClient`] — async handle owning the connection task.
+//! * [`ServerSnapshot`], [`ChannelInfo`], [`ClientInfo`] — opaque
+//!   DTOs containing only `String`s and primitives.
+//! * [`ProtocolError`] — typed error catalogue.
+//!
+//! ## What this crate does NOT expose
+//!
+//! * `tsclientlib::*` types.
+//! * `tsproto::*` types.
+//! * Any audio-related types — those live in `chanora_audio`.
+//!
+//! Promoted from `poc/tsclientlib-connect-spike` on 2026-05-14
+//! as part of the Alpha build.
 
 #![forbid(unsafe_code)]
 #![warn(missing_docs)]
 
+mod adapter;
+mod dto;
+
+pub use adapter::{ConnectConfig, ProtocolClient};
+pub use dto::{ChannelInfo, ClientInfo, ServerSnapshot};
+
 use thiserror::Error;
 
 /// Errors surfaced by the protocol adapter. None of these expose
-/// `tsclientlib`-specific types; raw upstream errors are mapped here.
+/// `tsclientlib`-specific types; raw upstream errors are mapped here
+/// to typed arms.
 #[derive(Debug, Error)]
 pub enum ProtocolError {
     /// Configuration is invalid before any I/O is attempted (bad
     /// hostname, missing identity, etc.).
     #[error("invalid protocol configuration: {0}")]
-    Invalid(&'static str),
-    /// The connect handshake failed.
+    Invalid(String),
+
+    /// Failed to dial / handshake with the server.
     #[error("connect failed: {0}")]
     Connect(String),
-    /// The connection ended unexpectedly.
-    #[error("disconnected: {0}")]
-    Disconnected(String),
+
+    /// The connection ended before becoming ready.
+    #[error("disconnected before ready: {0}")]
+    DisconnectedEarly(String),
+
+    /// Connection lost after becoming ready.
+    #[error("connection lost: {0}")]
+    Lost(String),
+
+    /// Identity parsing failed.
+    #[error("identity error: {0}")]
+    Identity(String),
+
     /// Operation timed out.
     #[error("protocol timeout")]
     Timeout,
-}
 
-/// Opaque identifier for a server-side channel. Replaces
-/// `tsclientlib::ChannelId` at the public boundary so its concrete
-/// representation can change without leaking through the rest of the
-/// codebase.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct ChannelId(pub u64);
-
-/// Opaque identifier for a server-side client.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub struct ClientId(pub u64);
-
-#[cfg(test)]
-mod tests {
-    #[test]
-    fn it_compiles() {}
+    /// A backend error escaped the mapping. Production callers
+    /// should never see this; if they do, it is a mapping bug here.
+    #[error("protocol backend: {0}")]
+    Backend(String),
 }