perf: overhaul session loading, caching, and runtime isolation (#2360)

Improve OpenChamber responsiveness under large session workloads while fixing
cache, synchronization, and persistence correctness across runtimes, projects,
directories, and worktrees.

- prioritize selected and visible sessions during bootstrap and defer
  non-critical enrichment work
- reduce redundant message loading, event processing, store publication, and
  hidden sidebar work
- prevent stale session and message requests from overwriting newer
  authoritative state
- preserve existing data when authoritative fetches fail instead of treating
  failures as successful empty responses
- scope session materialization, messages, drafts, queues, todos, pins,
  permissions, folders, tabs, Git state, and pull request data by runtime and
  directory identity
- harden runtime switching, reconnect, cleanup, mutation reconciliation, and
  persisted-state ordering
- preserve live subagent Task linkage when metadata arrives after an older
  message request or while streaming parts are suspended
- coalesce overlapping tail refreshes without losing newer refresh demand
- improve cold-session loading by moving deferrable work out of the critical
  bootstrap path
- isolate URL authentication, mobile credentials, native secrets, and other
  runtime-owned state across endpoint changes
- bound long-lived caches and remove avoidable allocations from event and
  rendering hot paths
- limit virtualization to archive collections where it improves rendering
  without disrupting active sidebar layout
- stabilize session folders, pin ordering, expanded state, and persisted
  sidebar behavior
- open skill files through the same secure editor and outside-workspace grant
  flow used by file navigation, including worktree sessions
- expand regression coverage for stale completions, runtime collisions,
  reconnect behavior, persistence races, authoritative empty results, and
  subagent refresh ordering
- document the updated synchronization, cache ownership, performance, and
  runtime-isolation invariants

packages/vscode/src/bridge-permission-auto-accept-runtime.test.ts

@@ -24,14 +24,36 @@ describe('VS Code permission auto-accept policy bridge', () => {
     }, context, dependencies);
 
     assert.equal(response?.success, true);
-    assert.deepEqual(response?.data, { sessions: { root: true } });
-    assert.deepEqual(broadcasts, [{ sessions: { root: true } }]);
+    assert.deepEqual(response?.data, { sessions: { root: true }, revision: 1 });
+    assert.deepEqual(broadcasts, [{ sessions: { root: true }, revision: 1 }]);
 
     const reloaded = await handlePermissionAutoAcceptBridgeMessage({
       id: '2',
       type: 'api:permission-auto-accept:get',
     }, context, dependencies);
-    assert.deepEqual(reloaded?.data, { sessions: { root: true } });
+    assert.deepEqual(reloaded?.data, { sessions: { root: true }, revision: 1 });
+  });
+
+  test('serializes concurrent writes without losing policy entries', async () => {
+    const context = createContext();
+    const dependencies = { broadcast: async () => undefined };
+    const first = handlePermissionAutoAcceptBridgeMessage({
+      id: '1',
+      type: 'api:permission-auto-accept:set',
+      payload: { sessionId: 'root', enabled: true },
+    }, context, dependencies);
+    const second = handlePermissionAutoAcceptBridgeMessage({
+      id: '2',
+      type: 'api:permission-auto-accept:set',
+      payload: { sessionId: 'child', enabled: false },
+    }, context, dependencies);
+
+    await Promise.all([first, second]);
+    const reloaded = await handlePermissionAutoAcceptBridgeMessage({
+      id: '3',
+      type: 'api:permission-auto-accept:get',
+    }, context, dependencies);
+    assert.deepEqual(reloaded?.data, { sessions: { root: true, child: false }, revision: 2 });
   });
 
   test('rejects malformed policy writes', async () => {