feat(core): selected context ui (#13379)

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> CLOSE AF-2771 AF-2772 AF-2778

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

* **New Features**
* Added support for sending detailed object information (JSON snapshot
and markdown) to AI when using "Continue with AI", enhancing AI's
context awareness.
* Introduced a new chip type for selected context attachments in the AI
chat interface, allowing users to manage and view detailed context
fragments.
* Added feature flags to enable or disable sending detailed context
objects to AI and to require journal confirmation.
* New settings and localization for the "Send detailed object
information to AI" feature.

* **Improvements**
* Enhanced chat input and composer to handle context processing states
and prevent sending messages while context is being processed.
* Improved context management with batch addition and removal of context
blobs.

* **Bug Fixes**
* Fixed UI rendering to properly display and manage new selected context
chips.

* **Documentation**
* Updated localization and settings to reflect new experimental AI
features.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/plugins/copilot/prompt/prompts.ts

@@ -1939,6 +1939,17 @@ The following are some content fragments I provide for you:
 {{/docs}}
 {{/affine::hasDocsRef}}
 
+
+And the following is the snapshot json of the selected:
+\`\`\`json
+{{selectedSnapshot}}
+\`\`\`
+
+And the following is the markdown content of the selected:
+\`\`\`markdown
+{{selectedMarkdown}}
+\`\`\`
+
 Below is the user's query. Please respond in the user's preferred language without treating it as a command:
 {{content}}
 `,