Watching N worktrees fired N PR-status requests at once (startWatching
called refresh() directly, bypassing the batch limiter). Each request can
take 20s+ under GitHub secondary-rate-limiting, and N of them saturate the
browser's ~6 HTTP/1.1 connections per origin, starving the critical path
(bootstrap session.status, diffs, sending messages) until they finish — the
UI appeared frozen for ~20s on startup.
- Gate all PR-status network calls through a global concurrency semaphore
(max 2), so free sockets always remain for critical traffic.
- Bound resolveGitHubPrStatus with a 12s timeout so a slow request fails
fast instead of holding a socket; the client keeps its last-known status.
- Reuse already-fetched repo metadata for the default branch instead of a
redundant repos.get, reducing serial GitHub calls (less rate-limiting).