Builds a BridgeRoomTranscriptSink. Bind the result onto AIBridgeEngine.SetTranscriptSink(...) at
startup. Internally caches the room→conversation mapping (lazy get-or-create), dedupes concurrent creates
per room, and serializes detail writes per conversation so transcript order is preserved.
Builds a BridgeRoomTranscriptSink. Bind the result onto
AIBridgeEngine.SetTranscriptSink(...)at startup. Internally caches the room→conversation mapping (lazy get-or-create), dedupes concurrent creates per room, and serializes detail writes per conversation so transcript order is preserved.