feat(agent-manager): reduce GitStatsPoller load by polling active worktree only

[Githubguy132010]

Context

Closes #8653.

A worktree with a large diff (e.g. 20 k lines) causes unnecessarily high RAM usage and HTTP traffic because GitStatsPoller called client.worktree.diffSummary() for every worktree on every 5-second tick, regardless of whether the user was looking at it.

PRStatusPoller already solves the same problem: it polls the active worktree every tick and does a full sync of all worktrees only every ~2 minutes. This PR applies the same pattern to GitStatsPoller.

Implementation

GitStatsPoller gains a setActiveWorktreeId(id) method (mirroring PRStatusPoller):

• On normal ticks, only the active worktree (the one whose session the user has open) is polled via diffSummary.
• Every FULL_SYNC_EVERY = 6 ticks (~30 s at the default 5 s interval), all non-missing worktrees are polled so inactive badges stay reasonably fresh.
• Calling setActiveWorktreeId with a new ID immediately triggers an out-of-band poll for that worktree, so the user sees fresh stats the moment they switch sessions — no extra wait.
• onStats always receives a complete snapshot: fresh data for polled worktrees + cached lastStats for non-polled ones. The webview contract is unchanged.
• tickCount is reset on stop() so restarted pollers always begin with a full sync.

AgentManagerProvider wires up the new call in the loadMessages and clearSession handlers, alongside the existing prBridge.poller.setActiveWorktreeId() call.

Screenshots

No UI changes — the stats numbers in the Agent Manager panel are unaffected; they just update with lower CPU/network overhead.

How to Test

1. Open the Agent Manager panel with 2+ worktrees, at least one with a large diff.
2. Open DevTools → Network tab, filter by XHR/Fetch.
3. Switch between sessions — confirm diffSummary is called only for the active worktree most of the time, and for all worktrees ~every 30 s.
4. Confirm stats numbers in the sidebar still update correctly.
5. Run the unit tests: cd packages/kilo-vscode && bun test tests/unit/git-stats-poller.test.ts (15 tests, 0 failures).

Get in Touch

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Files Reviewed (1 files)

• packages/kilo-vscode/src/agent-manager/GitStatsPoller.ts

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_{Reviewed by gpt-5.4-20260305 · 511,166 tokens}

[Githubguy132010]

Addressed both review warnings in 4745efe:

1. Busy-poll race — setActiveWorktreeId() now queues a pendingActiveWorktreeId when a fetch is in flight. After the fetch completes, the pending refresh fires immediately instead of waiting for the next scheduled tick.

2. clearSession load spike — activeWorktreeId === undefined no longer forces full sync on every tick. Instead, the same periodic cadence (FULL_SYNC_EVERY) applies whether or not an active worktree is set, so closing a session doesn't re-introduce the every-tick load.

Added tests for both fixes.