fix: setup skill reliability, requiresTrigger option, agent-browser visibility

Setup skill fixes:
- Run QR auth in foreground with long timeout, not background
- Replace fragile message-based registration with DB group sync lookup
- Personal chats: ask for phone number instead of querying empty DB
- Consolidate trigger word + security model + channel selection into one step
- Remove `timeout` shell command (unavailable on macOS), use Bash tool timeout
- Query 40 groups, display 10 at a time, support name lookup

requiresTrigger support:
- Add requiresTrigger field to RegisteredGroup type and DB schema
- Skip trigger check when requiresTrigger is false (for solo/personal chats)
- Main group still always processes all messages (unchanged)

Agent-browser visibility:
- Append global CLAUDE.md to non-main agent system prompts via SDK
- Add browser tool docs to global and main CLAUDE.md
- Update skill description to be broader (not just "web testing")
- Reference agent-browser.md in root CLAUDE.md key files

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -16,6 +16,7 @@ Single Node.js process that connects to WhatsApp, routes messages to Claude Agen
 | `src/task-scheduler.ts` | Runs scheduled tasks |
 | `src/db.ts` | SQLite operations |
 | `groups/{name}/CLAUDE.md` | Per-group memory (isolated) |
+| `container/skills/agent-browser.md` | Browser automation tool (available to all agents via Bash) |
 
 ## Skills