feat(server): realtime notification & task status (#14934)

#### PR Dependency Tree


* **PR #14934** 👈

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**
* Full realtime platform added: live notifications, comments, embedding
progress, and transcription task updates via realtime subscriptions.

* **Chores**
* Frontend switched from polling/GraphQL queries to realtime channels;
legacy query fields marked deprecated and client libs updated to use
realtime APIs.

[![Review Change
Stack](https://storage.googleapis.com/coderabbit_public_assets/review-stack-in-coderabbit-ui.svg)](https://app.coderabbit.ai/change-stack/toeverything/AFFiNE/pull/14934)
<!-- end of auto-generated comment: release notes by coderabbit.ai -->


#### PR Dependency Tree


* **PR #14934** 👈
  * **PR #14936**

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

yarn.lock

@@ -818,6 +818,7 @@ __metadata:
     "@affine/error": "workspace:*"
     "@affine/graphql": "workspace:*"
     "@affine/reader": "workspace:*"
+    "@affine/realtime": "workspace:*"
     "@blocksuite/affine": "workspace:*"
     "@toeverything/infra": "workspace:*"
     eventemitter2: "npm:^6.4.9"
@@ -835,6 +836,7 @@ __metadata:
   peerDependencies:
     "@affine/error": "workspace:*"
     "@affine/graphql": "workspace:*"
+    "@affine/realtime": "workspace:*"
     "@blocksuite/affine": "workspace:*"
     idb: ^8.0.0
     socket.io-client: ^4.8.3
@@ -866,6 +868,14 @@ __metadata:
   languageName: unknown
   linkType: soft
 
+"@affine/realtime@workspace:*, @affine/realtime@workspace:packages/common/realtime":
+  version: 0.0.0-use.local
+  resolution: "@affine/realtime@workspace:packages/common/realtime"
+  dependencies:
+    "@affine/graphql": "workspace:*"
+  languageName: unknown
+  linkType: soft
+
 "@affine/revert-update@workspace:tools/revert-update":
   version: 0.0.0-use.local
   resolution: "@affine/revert-update@workspace:tools/revert-update"
@@ -918,6 +928,7 @@ __metadata:
     "@affine-tools/cli": "workspace:*"
     "@affine-tools/utils": "workspace:*"
     "@affine/graphql": "workspace:*"
+    "@affine/realtime": "workspace:*"
     "@affine/s3-compat": "workspace:*"
     "@affine/server-native": "workspace:*"
     "@apollo/server": "npm:^5.5.0"