- implement chat query filtering and message search endpoints
- add db indexes for search fields
- activate chats search input in web
- replace inline create panel with floating TG-style action menu
- add owner/admin/member permission checks
- implement member add/remove, role updates, and leave flow
- add chat title update endpoint for manageable chat types
- add media preview and upload confirmation for image/video
- add upload progress tracking for presigned uploads
- keep voice recording/upload flow with better UI states
- include related realtime/chat updates currently in working tree
