Initial MCM project: FastAPI + Textual TUI unified messenger

MultiCustomerMessenger supporting Telegram (python-telegram-bot),
WhatsApp (Green API) and SMS (python-gsmmodem-new). REST API with
Bearer-token auth, SQLAlchemy models for MariaDB, APScheduler for
background polling, and Textual TUI running in same asyncio event-loop.

main_api_only.py

@@ -0,0 +1,12 @@
+"""MCM API-only Einstiegspunkt – wird vom systemd-Dienst verwendet."""
+
+import asyncio
+import sys
+
+from main import main
+
+if __name__ == "__main__":
+    try:
+        asyncio.run(main(with_tui=False))
+    except KeyboardInterrupt:
+        sys.exit(0)