The TUI is fully interactive from the first frame but `session.create`
(agent + tools + MCP) takes ~2s. Plain-text messages typed before the
session is live used to fail with "session not ready yet"; slash and
shell commands worked but agent prompts were dropped.
Now:
- `dispatchSubmission` enqueues plain text when `sid` is null (slash/shell
still short-circuit first)
- `useMainApp` tracks sid transitions and kicks off one `sendQueued()`
when the session first becomes ready; subsequent queued messages drain
on `message.complete` as before
- Fixed pre-existing double-Enter bug that dequeued without sid check
User flow: type `hello` → shows in `queuedDisplay` preview → 2s later
agent wakes → message auto-sends → reply streams. Zero wasted input.
f3920fec0b