feat(server): adapt gemini3.1 preview (#14583)

#### PR Dependency Tree


* **PR #14583** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added Gemini 3.1 Pro Preview support (text, image, audio) and new
GPT‑5 variants as defaults; centralized persistent telemetry state for
more reliable client identity.

* **UX**
  * Improved model submenu placement in chat preferences.
* More robust mindmap parsing, preview, regeneration and replace
behavior.

* **Chores**
  * Bumped AI SDK and related dependencies.

* **Tests**
  * Expanded/updated tests and increased timeouts for flaky flows.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/track/src/state.ts

@@ -0,0 +1,99 @@
+import { nanoid } from 'nanoid';
+
+export type TrackProperties = Record<string, unknown> | undefined;
+
+export type Middleware = (
+  name: string,
+  properties?: TrackProperties
+) => Record<string, unknown>;
+
+type TrackerState = {
+  enabled: boolean;
+  clientStorage: Storage | null;
+  clientId: string;
+  pendingFirstVisit: boolean;
+  sessionId: number;
+  sessionNumber: number;
+  lastActivityMs: number;
+  sessionStartSent: boolean;
+  engagementTrackingEnabled: boolean;
+  visibleSinceMs: number | null;
+  pendingEngagementMs: number;
+  visibilityChangeHandler: (() => void) | null;
+  pageHideHandler: (() => void) | null;
+  userId: string | undefined;
+  userProperties: Record<string, unknown>;
+  middlewares: Set<Middleware>;
+};
+
+const CLIENT_ID_KEY = 'affine_telemetry_client_id';
+
+export let trackerState = createTrackerState();
+
+export function resetTrackerState() {
+  cleanupTrackerState(trackerState);
+  trackerState = createTrackerState();
+}
+
+function createTrackerState(): TrackerState {
+  const clientStorage = localStorageSafe();
+  const hasClientId = !!clientStorage?.getItem(CLIENT_ID_KEY);
+
+  return {
+    enabled: true,
+    clientStorage,
+    clientId: readPersistentId(CLIENT_ID_KEY, clientStorage),
+    pendingFirstVisit: !hasClientId,
+    sessionId: 0,
+    sessionNumber: 0,
+    lastActivityMs: 0,
+    sessionStartSent: false,
+    engagementTrackingEnabled: false,
+    visibleSinceMs: null,
+    pendingEngagementMs: 0,
+    visibilityChangeHandler: null,
+    pageHideHandler: null,
+    userId: undefined,
+    userProperties: {},
+    middlewares: new Set<Middleware>(),
+  };
+}
+
+function cleanupTrackerState(state: TrackerState) {
+  if (state.visibilityChangeHandler && typeof document !== 'undefined') {
+    document.removeEventListener(
+      'visibilitychange',
+      state.visibilityChangeHandler
+    );
+  }
+  if (state.pageHideHandler && typeof window !== 'undefined') {
+    window.removeEventListener('pagehide', state.pageHideHandler);
+  }
+}
+
+function readPersistentId(key: string, storage: Storage | null, renew = false) {
+  if (!storage) {
+    return nanoid();
+  }
+  if (!renew) {
+    const existing = storage.getItem(key);
+    if (existing) {
+      return existing;
+    }
+  }
+  const id = nanoid();
+  try {
+    storage.setItem(key, id);
+  } catch {
+    return id;
+  }
+  return id;
+}
+
+function localStorageSafe(): Storage | null {
+  try {
+    return typeof localStorage === 'undefined' ? null : localStorage;
+  } catch {
+    return null;
+  }
+}