feat(editor): extract chat runtime (#14937)

#### PR Dependency Tree


* **PR #14937** 👈

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**
* Centralized AI event system and a runtime powering chat sessions and
actions.

* **Improvements**
* Chat UI (composer, messages, toolbar, tabs, panels) now syncs with
runtime snapshots for more consistent state.
* Improved session/tab lifecycle (create, fork, delete), context
embedding status, and history handling.
* More reliable send/stop/retry flows, better telemetry scoping, and
clearer upgrade/login/insert-template prompts.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/core/src/modules/peek-view/view/doc-preview/doc-peek-view.tsx

@@ -1,6 +1,6 @@
 import { Scrollable } from '@affine/component';
 import { PageDetailLoading } from '@affine/component/page-detail-skeleton';
-import { type AIChatParams, AIProvider } from '@affine/core/blocksuite/ai';
+import { AIAppEvents, type AIChatParams } from '@affine/core/blocksuite/ai';
 import type { AffineEditorContainer } from '@affine/core/blocksuite/block-suite-editor';
 import { EditorOutlineViewer } from '@affine/core/blocksuite/outline-viewer';
 import { AffineErrorBoundary } from '@affine/core/components/affine/affine-error-boundary';
@@ -137,12 +137,8 @@ function DocPeekPreviewEditor({
         // chat panel open is already handled in <DetailPageImpl />
       }
     };
-    disposables.push(
-      AIProvider.slots.requestOpenWithChat.subscribe(openHandler)
-    );
-    disposables.push(
-      AIProvider.slots.requestSendWithChat.subscribe(openHandler)
-    );
+    disposables.push(AIAppEvents.requestOpenWithChat.subscribe(openHandler));
+    disposables.push(AIAppEvents.requestSendWithChat.subscribe(openHandler));
     return () => disposables.forEach(d => d.unsubscribe());
   }, [doc, peekView, workbench, workspace.id]);