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.

api/routes/messages.py

@@ -0,0 +1,44 @@
+from fastapi import APIRouter, Depends, HTTPException, Query
+from sqlalchemy.orm import Session
+
+from api.auth import require_api_key
+from db.database import get_db
+from schemas import MessageResponse, SendMessageRequest
+from services import message_service
+
+router = APIRouter(prefix="/messages", tags=["messages"])
+
+
+@router.post("/", response_model=MessageResponse, status_code=201)
+async def send_message(
+    req: SendMessageRequest,
+    db: Session = Depends(get_db),
+    _: str = Depends(require_api_key),
+):
+    if req.channel == "telegram" and not req.recipient_telegram_id:
+        raise HTTPException(status_code=422, detail="recipient_telegram_id required for Telegram")
+    if req.channel in ("whatsapp", "sms") and not req.recipient_phone:
+        raise HTTPException(status_code=422, detail="recipient_phone required for WhatsApp/SMS")
+
+    msg = await message_service.send(db, req)
+    return MessageResponse.model_validate(msg)
+
+
+@router.get("/", response_model=list[MessageResponse])
+def list_messages(
+    conversation_id: str | None = Query(None),
+    channel: str | None = Query(None),
+    limit: int = Query(50, ge=1, le=200),
+    offset: int = Query(0, ge=0),
+    db: Session = Depends(get_db),
+    _: str = Depends(require_api_key),
+):
+    from db.models import Message
+
+    q = db.query(Message)
+    if conversation_id:
+        q = q.filter(Message.conversation_id == conversation_id)
+    if channel:
+        q = q.filter(Message.channel == channel)
+    msgs = q.order_by(Message.created_at.desc()).offset(offset).limit(limit).all()
+    return [MessageResponse.model_validate(m) for m in msgs]