Add @mention support in AI Chat input (#17943)

## Summary
- Add `@mention` support to the AI Chat text input by replacing the
plain textarea with a minimal Tiptap editor and building a shared
`mention` module with reusable Tiptap extensions (`MentionTag`,
`MentionSuggestion`), search hook (`useMentionSearch`), and suggestion
menu — all shared with the existing BlockNote-based Notes mentions to
avoid code duplication
- Mentions are serialized as
`[[record:objectName:recordId:displayName]]` markdown (the format
already understood by the backend and rendered in chat messages), and
displayed using the existing `RecordLink` chip component for visual
consistency
- Fix images in chat messages overflowing their container by
constraining to `max-width: 100%`
- Fix web_search tool display showing literal `{query}` instead of the
actual query (ICU single-quote escaping issue in Lingui `t` tagged
templates)

## Test plan
- [ ] Open AI Chat, type `@` and verify the suggestion menu appears with
searchable records
- [ ] Select a mention from the dropdown (via click or keyboard
Enter/ArrowUp/Down) and verify the record chip renders inline
- [ ] Send a message containing a mention and verify it appears
correctly in the conversation as a clickable `RecordLink`
- [ ] Verify Enter sends the message when the suggestion menu is closed,
and selects a mention when the menu is open
- [ ] Verify images in AI chat responses are constrained to the
container width
- [ ] Verify the web_search tool step shows the actual search query
(e.g. "Searched the web for Salesforce") instead of `{query}`
- [ ] Verify Notes @mentions still work as before


Made with [Cursor](https://cursor.com)

---------

Co-authored-by: Cursor <cursoragent@cursor.com>

packages/twenty-front/src/modules/blocknote-editor/utils/prepareBodyWithSignedUrls.ts

@@ -0,0 +1,30 @@
+import type { PartialBlock } from '@blocknote/core';
+
+// TODO: This function is extracted but its not doing what it is supposed to do. It is not signing the urls. It is just parsing the image urls.
+// tracking issue - https://github.com/twentyhq/twenty/issues/8351
+export const prepareBodyWithSignedUrls = (
+  newStringifiedBody: string,
+): string => {
+  if (!newStringifiedBody) return newStringifiedBody;
+
+  const body: PartialBlock[] = JSON.parse(newStringifiedBody);
+
+  const bodyWithSignedPayload = body.map((block) => {
+    if (block.type !== 'image' || !block.props?.url) {
+      return block;
+    }
+
+    const imageUrl = block.props.url;
+    const parsedImageUrl = new URL(imageUrl);
+
+    return {
+      ...block,
+      props: {
+        ...block.props,
+        url: parsedImageUrl.toString(),
+      },
+    };
+  });
+
+  return JSON.stringify(bodyWithSignedPayload);
+};