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

<img width="1133" height="982" alt="截屏2025-07-31 17 56 24"
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<img width="1151" height="643" alt="截屏2025-07-31 17 55 32"
src="https://github.com/user-attachments/assets/b2320023-ab75-4455-9c24-d133fda1b7e1"
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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/frontend/core/src/modules/feature-flag/constant.ts

@@ -264,6 +264,23 @@ export const AFFINE_FLAGS = {
     configurable: isCanaryBuild,
     defaultState: false,
   },
+  enable_two_step_journal_confirmation: {
+    category: 'affine',
+    displayName: 'Enable Two Step Journal Confirmation',
+    description:
+      'When enabled, you must confirm the journal before you can create a new journal.',
+    configurable: isCanaryBuild,
+    defaultState: isCanaryBuild,
+  },
+  enable_send_detailed_object_to_ai: {
+    category: 'affine',
+    displayName:
+      'com.affine.settings.workspace.experimental-features.enable-ai-send-detailed-object.name',
+    description:
+      'com.affine.settings.workspace.experimental-features.enable-ai-send-detailed-object.description',
+    configurable: true,
+    defaultState: true,
+  },
 } satisfies { [key in string]: FlagInfo };
 
 // oxlint-disable-next-line no-redeclare