Adds full support for self-messaging setups where you chat with yourself
and an AI assistant replies in the same WhatsApp bubble.
Changes:
- Same-phone mode (from === to) always allowed, bypasses allowFrom check
- Echo detection via bounded Set (max 100) prevents infinite loops
- Configurable samePhoneMarker in config (default: "[same-phone]")
- Messages prefixed with marker so assistants know the context
- fromMe filter removed from inbound.ts (echo detection in auto-reply)
- Verbose logging for same-phone detection and echo skips
Tests:
- Same-phone allowed without/despite allowFrom configuration
- Body prefixed only when from === to
- Non-same-phone rejected when not in allowFrom
