feat(core): extract md & snapshot & attachments from selected (#13312)

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

## Summary by CodeRabbit

* **New Features**
* Enhanced extraction of selected content in the editor to include
document snapshots, markdown summaries, and attachments for both
edgeless and page modes.
* Attachments related to selected content are now available in chat and
input contexts, providing additional metadata.
* Added utility to identify and retrieve selected attachments in editor
content.

* **Bug Fixes**
* Improved consistency in attachment retrieval when extracting selected
content.

* **Chores**
* Updated dependencies and workspace references to include new block
suite components.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

> CLOSE AF-2770

packages/frontend/core/package.json

@@ -20,6 +20,7 @@
     "@affine/templates": "workspace:*",
     "@affine/track": "workspace:*",
     "@blocksuite/affine": "workspace:*",
+    "@blocksuite/affine-block-root": "workspace:*",
     "@blocksuite/affine-components": "workspace:*",
     "@blocksuite/affine-shared": "workspace:*",
     "@blocksuite/global": "workspace:*",