feat: Sprint 4 — rich messaging: receipts, typing, reactions, edit/delete
- Auto-send read receipts on Chat/Reply receive, display "✓ read"
notification (loop-safe: only Chat/Reply trigger receipts)
- Typing indicators with /typing command, 10s timeout expiry,
/typing-notify toggle, ephemeral (not stored in DB)
- /react <emoji> [index] command for message reactions, display
inline with sender name
- Add Edit (0x06) and Delete (0x07) AppMessage variants with
serialize/parse, /edit and /delete REPL commands (own messages
only), incoming edit/delete handling with DB updates
- 3 new roundtrip tests for Edit/Delete serialization (70 core tests)
Chris Nennemann
81d5e2e590