feat(bridge,android): BridgeEvent::PermissionState + JNI publish hook + c++_shared link

Per SDD-106 §5 add BridgeEvent::PermissionState{permission, state}
with the PermissionStateKind enum (Granted, Denied, PermanentlyDenied,
Unknown). The Kotlin side publishes mid-session permission changes
through a new JNI entry point Java_app_chanora_chanora_1flutter
_MainActivity_publishPermissionState routed by the new
permission_jni.rs module; the Rust audio engine subscribes and
authoritatively clamps the transmit gate (see SDD-106 §6).

Adds crates/chanora_bridge/build.rs to emit
cargo:rustc-link-lib=dylib=c++_shared on Android so libchanora_bridge
.so carries DT_NEEDED libc++_shared.so; this is required by Android
API 24+ per-library linker namespaces to resolve __cxa_pure_virtual
and friends at System.loadLibrary time.

Includes the FRB-regenerated Dart counterparts so each commit is
independently buildable.

Trace: SDD-105, SDD-106 §5, SDD-118 item 6 (extended).

crates/chanora_bridge/Cargo.toml

@@ -18,6 +18,7 @@ crate-type = ["cdylib", "staticlib", "rlib"]
 [dependencies]
 chanora_core = { path = "../../core/chanora_core" }
 chanora_protocol = { path = "../chanora_protocol" }
+chanora_audio = { path = "../chanora_audio" }
 flutter_rust_bridge = "=2.12.0"
 thiserror.workspace = true
 serde.workspace = true