perf(agent-manager): skip git stats polling for worktrees in collapsed sections (#8903)

Sync GitStatsPoller skip set with collapsed section state via pushState(),
saving 1 aheadBehind subprocess + 1 diffSummary HTTP call per hidden
worktree per poll cycle.

Closes #8900

packages/kilo-vscode/src/agent-manager/AgentManagerProvider.ts

@@ -789,6 +789,7 @@ export class AgentManagerProvider implements Disposable {
       return null
     }
     // Remove from state BEFORE disk removal so pollers immediately stop targeting this worktree.
+    // Pre-emptive skip covers any in-flight poll that already captured getWorktrees().
     this.statsPoller.skipWorktree(worktreeId)
     this.prBridge.remove(worktreeId)
     this.run.remove(worktreeId)
@@ -1251,6 +1252,18 @@ export class AgentManagerProvider implements Disposable {
     }
   }
 
+  /** Sync the poller's skip set with currently collapsed sections. */
+  private syncPollerSkips(): void {
+    const state = this.state
+    if (!state) return
+    const skipped = new Set<string>()
+    for (const sec of state.getSections()) {
+      if (!sec.collapsed) continue
+      for (const id of state.getWorktreesInSection(sec.id)) skipped.add(id)
+    }
+    this.statsPoller.syncSkips(skipped)
+  }
+
   private pushState(): void {
     const state = this.state
     if (!state) return
@@ -1272,6 +1285,9 @@ export class AgentManagerProvider implements Disposable {
       ...run,
     })
 
+    // Sync skip set before enabling the poller so the first poll cycle
+    // already excludes worktrees in collapsed sections.
+    this.syncPollerSkips()
     this.statsPoller.setEnabled(worktrees.length > 0 || this.panel !== undefined)
     this.prBridge.poller.setEnabled(worktrees.length > 0)
   }

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

@@ -84,12 +84,14 @@ export class GitStatsPoller {
     }
   }
 
-  skipWorktree(id: string): void {
-    this.skipWorktreeIds.add(id)
+  /** Replace the entire skip set with the given IDs. */
+  syncSkips(ids: Set<string>): void {
+    this.skipWorktreeIds = ids
   }
 
-  unskipWorktree(id: string): void {
-    this.skipWorktreeIds.delete(id)
+  /** Pre-emptively exclude a single worktree (e.g. before deletion). */
+  skipWorktree(id: string): void {
+    this.skipWorktreeIds.add(id)
   }
 
   setEnabled(enabled: boolean): void {

packages/kilo-vscode/src/agent-manager/WorktreeStateManager.ts

@@ -352,6 +352,15 @@ export class WorktreeStateManager {
     return this.sections.get(id)
   }
 
+  /** Return IDs of worktrees assigned to the given section. */
+  getWorktreesInSection(id: string): string[] {
+    const result: string[] = []
+    for (const wt of this.worktrees.values()) {
+      if (wt.sectionId === id) result.push(wt.id)
+    }
+    return result
+  }
+
   addSection(name: string, color: string | null, worktreeIds?: string[]): Section {
     this.setNormalizedWorktreeOrder(this.worktreeOrder)
     const id = generateId("sec")