add bounded repository-scoped teammate lookup behind the authenticated dashboard API
add reusable touch/keyboard accessible mention autocomplete to issue, pull-request, and unread-update composers
preserve literal typing and drafts when lookup is unavailable; suppress stale repository responses
precache the new runtime for the offline shell
Verification
RED observed for missing proxy behavior, API route, mention insertion/controller, and three-composer integration
python3 -m pytest tests/ -q → 862 passed
Chromium mobile render at 320×568 and 390×844 → no horizontal overflow, 44px options, contained listbox
Closes #447
## What changed
- add bounded repository-scoped teammate lookup behind the authenticated dashboard API
- add reusable touch/keyboard accessible mention autocomplete to issue, pull-request, and unread-update composers
- preserve literal typing and drafts when lookup is unavailable; suppress stale repository responses
- precache the new runtime for the offline shell
## Verification
- RED observed for missing proxy behavior, API route, mention insertion/controller, and three-composer integration
- `python3 -m pytest tests/ -q` → 862 passed
- Chromium mobile render at 320×568 and 390×844 → no horizontal overflow, 44px options, contained listbox
Blocking a user prevents them from interacting with repositories, such as opening or commenting on pull requests or issues. Learn more about blocking a user.
Closes #447
What changed
Verification
python3 -m pytest tests/ -q→ 862 passed