- Adds `@` autocomplete to the internal comments composer on work order detail (`/workorders/:id`).
- Encodes selected users as `@[userId:Display Name]` tokens in comment text so mentions stay readable when the backend ignores the optional payload field.
- Sends `mentions: string[]` on `POST workorders/{id}/comments` when the composer contains encoded tokens.
- Highlights mentions in the comment thread using encoded tokens and/or `mentions` returned by the API.
## Out of scope
- Notification Center deep-linking for mention events.
- Backend notification triggers beyond the FE payload.
## BE contract
See `docs/work-orders/pending-be-contract.md` (Comments section):