perf(sidebar): index session ownership and narrow live subscriptions

Replace repeated project-by-session directory matching across sidebar hooks with a shared ownership index that resolves each unique directory once and exposes direct project and folder-scope buckets.

Gate destructive folder reconciliation on authoritative session data and topology readiness, preserve last-known worktrees after discovery failures, and retain nested-project, VS Code, active/archive dedupe, and Windows drive-root semantics.

Narrow cross-directory subscriptions to session and status slices so streaming deltas no longer trigger global aggregation. Reuse a cached session ID index for permission lineage checks instead of rebuilding it on every session switch.

On the reported 15-project, 67-worktree, 14,561-session shape, ownership indexing averages 3.81 ms versus roughly 450 ms for the cache-only hotfix.

Validation: 28 targeted tests, UI type-check, UI lint, and dead-code analysis.

packages/ui/src/stores/utils/permissionAutoAccept.test.ts

@@ -60,6 +60,17 @@ describe("autoRespondsPermission", () => {
     })).toBe(true)
   })
 
+  test("uses a prebuilt session index for lineage lookup", () => {
+    const parent = makeSession("parent")
+    const child = makeSession("child", "parent")
+    expect(autoRespondsPermission({
+      autoAccept: { parent: true },
+      sessions: [],
+      sessionById: new Map([[parent.id, parent], [child.id, child]]),
+      sessionID: "child",
+    })).toBe(true)
+  })
+
   test("returns false when only sibling has autoAccept enabled", () => {
     const autoAccept: PermissionAutoAcceptMap = { sibling: true }
     const sessions = [

packages/ui/src/stores/utils/permissionAutoAccept.ts

@@ -10,8 +10,12 @@ const buildSessionMap = (sessions: Session[]): Map<string, Session> => {
   return map;
 };
 
-const resolveLineage = (sessionID: string, sessions: Session[]): string[] => {
-  const map = buildSessionMap(sessions);
+const resolveLineage = (
+  sessionID: string,
+  sessions: Session[],
+  sessionById?: ReadonlyMap<string, Session>,
+): string[] => {
+  const map = sessionById ?? buildSessionMap(sessions);
   const result: string[] = [];
   const seen = new Set<string>();
   let current: string | undefined = sessionID;
@@ -28,10 +32,12 @@ const resolveLineage = (sessionID: string, sessions: Session[]): string[] => {
 export const autoRespondsPermission = (input: {
   autoAccept: PermissionAutoAcceptMap;
   sessions: Session[];
+  sessionById?: ReadonlyMap<string, Session>;
   sessionID: string;
 }): boolean => {
-  const { autoAccept, sessions, sessionID } = input;
-  const lineage = resolveLineage(sessionID, sessions);
+  const { autoAccept, sessions, sessionById, sessionID } = input;
+  if (Object.keys(autoAccept).length === 0) return false;
+  const lineage = resolveLineage(sessionID, sessions, sessionById);
 
   for (const id of lineage) {
     if (!Object.prototype.hasOwnProperty.call(autoAccept, id)) {