chore(server): improve transcript stability (#13821)

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

* **New Features**
* Enhanced audio/video detection for MP4 files to better distinguish
audio-only vs. video.

* **Dependencies**
* Added MP4 parsing dependency and updated AI provider libraries
(Anthropic, Google, OpenAI, etc.).

* **Bug Fixes**
  * Tightened authentication state validation for magic-link/OTP flows.
* Stricter space-join validation to reject invalid client
types/versions.
  * Improved transcript entry deduplication and data handling.

* **API**
* Transcript submit payload now requires infos and removes deprecated
url/mimeType fields.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/core/auth/controller.ts

@@ -270,14 +270,12 @@ export class AuthController {
     validators.assertValidEmail(email);
 
     const cacheKey = OTP_CACHE_KEY(otp);
-    const cachedToken = await this.cache.get<
-      { token: string; clientNonce: string } | string
-    >(cacheKey);
+    const cachedToken = await this.cache.get<{
+      token: string;
+      clientNonce: string;
+    }>(cacheKey);
     let token: string | undefined;
-    // TODO(@fengmk2): this is a temporary compatible with cache token is string value, should be removed in 0.22
-    if (typeof cachedToken === 'string') {
-      token = cachedToken;
-    } else if (cachedToken) {
+    if (cachedToken && typeof cachedToken === 'object') {
       token = cachedToken.token;
       if (cachedToken.clientNonce && cachedToken.clientNonce !== clientNonce) {
         throw new InvalidAuthState();

packages/backend/server/src/core/sync/gateway.ts

@@ -194,14 +194,12 @@ export class SpaceSyncGateway
     @ConnectedSocket() client: Socket,
     @MessageBody()
     { spaceType, spaceId, clientVersion }: JoinSpaceMessage
-  ): Promise<EventResponse<{ clientId: string; success: true }>> {
-    // TODO(@forehalo): remove this after 0.19 goes out of life
-    // simple match 0.19.x
-    if (/^0.19.[\d]$/.test(clientVersion)) {
-      const room = Room(spaceId, 'sync-019');
-      if (!client.rooms.has(room)) {
-        await client.join(room);
-      }
+  ): Promise<EventResponse<{ clientId: string; success: boolean }>> {
+    if (
+      ![SpaceType.Userspace, SpaceType.Workspace].includes(spaceType) ||
+      /^0.1/.test(clientVersion)
+    ) {
+      return { data: { clientId: client.id, success: false } };
     } else {
       if (spaceType === SpaceType.Workspace) {
         this.event.emit('workspace.embedding', { workspaceId: spaceId });