Move the renderer-side AI-streaming runtime (IpcChatTransport,
TopicStreamSubscription, streamDispatchCoordinator) out of the top-level
src/renderer/transport/ directory into the shared services/aiTransport/
bucket. By shape these are stateful runtime singletons/classes, and the
runtime is cross-surface (consumed by chat, quick-assistant, selection),
so per the renderer architecture it routes into services/, not its own
top-level directory.
- Add a curated index.ts barrel exposing only the externally consumed
symbols (ipcChatTransport, TopicStreamSubscription, ExecutionTerminal);
the class, dispatch coordinator and helpers stay private.
- Update the 6 consumer sites (5 imports + 1 vi.mock) to the barrel.
- Sync architecture and AI docs to the new path; drop the now-resolved
transport/ deviation from the renderer-architecture pending table.
