Generic extension point in community codebase: PreDispatchHook type
registered in AppState, checked before every agent_query dispatch.
Enables Pro features like budget enforcement and branch policy.
Adds trash icon button in Messages header that clears all communications
for the active group: DMs, channel messages, activity feed, seen tracking,
and dead letters. Shows Tauri warning dialog with confirmation before delete.
- Rust: clear_all_communications() in btmsg.rs (4 DELETE queries)
- Tauri command: btmsg_clear_all_comms
- Bridge: clearAllComms(groupId)
- UI: trash button with hover-red styling, resets all local state after clear
