The @mention dropdown was only in command-input.tsx but users type in chat-input.tsx (the v3.0 chat textarea). Added @mention support there: - @mention state and detection logic - PatientMentionDropdown rendering - handleMentionSelect with activePatient setting - Escape key closes dropdown before clearing input 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>