Treat OpenCode slash-command header timeouts as recoverable transport failures so Paseo waits for the SSE terminal event instead of failing the turn immediately.
Add a regression test for the timeout path to keep slash commands aligned with the existing event-stream completion flow.
Reconcile OpenCode provider state when Paseo closes or archives an agent so upstream sessions do not remain active after local teardown.
Keep the close path idempotent by attempting an abort first and then marking the upstream session archived even when the run is already idle or missing.
Fixes#400
Co-authored-by: OpenCode <noreply@openai.com>
