Update LiveKitSession tests to use _state discriminated union instead of
old flat field names (room, currentChannelId, latestToken, etc.) removed
in the state machine refactor. Also fix renderers.test.ts URL resolution
by setting a server host in beforeEach so isSafeUrl can parse relative
attachment URLs in jsdom. Stage all four Go test files so the CI Go job
runs them.
Additionally fix a regression in connectAndSetup's finally block: when a
pendingJoin is queued during a stale-join abort, preserve the connecting
state so handleVoiceToken's drain loop can pick it up rather than losing
it by resetting to idle.