Note

Medium Risk
Changes timing and ordering of preview discovery and Git ref freshness paths that many UI surfaces depend on; regressions could show stale ports/refs or missed updates, but scope is bounded and covered by new port-scanner tests.

Overview
Reduces steady background subprocess and RPC churn from Git ref listing and preview port discovery, aimed at lowering idle CPU/memory use during long sessions.

Git refs (vcs.ts) — First-page ref lists revalidate every 20s (was 5s). Inactive ref atoms expire after 30s (was 5 minutes). Paginated/cursor listRefs queries no longer tick on an interval; they fetch once per connected generation.

UI (DiffPanel.tsx) — Opening the branch comparison ref combobox calls refresh() on local and remote ref queries so the menu is up to date without waiting for the slower background interval.

Preview ports (PortScanner.ts, ws.ts) — Replaces a fixed 3s lsof/probe loop with 10s when a listener is known and 20s when idle or empty. retain still triggers an immediate scan when discovery was idle; subscribe replays lastSnapshot under a semaphore so replay and broadcasts cannot reorder. Unchanged terminal PID registrations and no-op unregisters skip extra scans; real changes still pollTick immediately. WebSocket subscribeDiscoveredLocalServers drops the extra scan() on subscribe and relies on retain + subscribe replay.

Tests — Adds coverage for unchanged registration deduping and ordered delivery under concurrent replay/broadcast.

Docs — Adds BRANCH_DETAILS.md describing expected behavior and dev ports.

^{Reviewed by Cursor Bugbot for commit 8f2fdbb. Bugbot is set up for automated code reviews on this repo. Configure here.}

Note

Reduce background Git ref and port polling frequency

• Increases Git ref revalidation interval from 5s to 20s and sets idle atom TTL to 30s; paginated/cursor pages are now one-shot fetches with no periodic revalidation (vcs.ts)
• Replaces the fixed 3s port scan loop with an adaptive loop sleeping 10s when active and 20s when idle or no servers are known (PortScanner.ts)
• Serializes snapshot broadcasts and subscriber replay via a Semaphore, preventing out-of-order delivery and stale replays after newer scans
• Skips polling when terminal registrations or unregistrations are unchanged, triggering immediate scans only on actual changes
• Opening the comparison-ref menu in DiffPanel now triggers an immediate refresh of local and remote branch refs

^{Macroscope summarized 8f2fdbb.}