added burger menu with admin page and user invitation link generation

src/baby_monitor/routers/admin.py

@@ -0,0 +1,66 @@
+"""Admin router for administrative functions."""
+
+import secrets
+from datetime import datetime, timedelta, UTC
+from typing import Annotated
+from fastapi import APIRouter, Depends
+from pydantic import BaseModel
+
+from baby_monitor.routers.auth import verify_admin
+from baby_monitor.repositories.dependencies.get_invitation_repository import (
+    get_invitation_repository,
+)
+from baby_monitor.repositories.interfaces import (
+    InvitationRepositoryInterface,
+)
+
+router = APIRouter(prefix="/api/admin", tags=["admin"])
+
+
+class InvitationResponse(BaseModel):
+    """Response model for invitation link generation."""
+
+    token: str
+    expires_at: str
+    message: str
+
+
+@router.post("/generate-invitation", response_model=InvitationResponse)
+async def generate_invitation_link(
+    user_id: Annotated[int, Depends(verify_admin)],
+    invitation_repository: Annotated[
+        InvitationRepositoryInterface,
+        Depends(get_invitation_repository),
+    ],
+) -> InvitationResponse:
+    """Generate a new invitation link for user registration.
+    
+    The invitation token is valid for 24 hours and can be used once.
+    Requires admin role.
+    
+    Args:
+        user_id: Admin user ID (from verify_admin)
+        invitation_repository: Invitation storage backend
+    
+    Returns:
+        InvitationResponse with token and expiration details
+    """
+    
+    # Generate secure random token
+    invitation_token = secrets.token_urlsafe(32)
+    
+    # Calculate expiration (24 hours from now)
+    expires_at = datetime.now(UTC) + timedelta(hours=24)
+    
+    # Store invitation token in database
+    invitation_repository.create_invitation(
+        token=invitation_token,
+        created_by_user_id=user_id,
+        expires_at=expires_at,
+    )
+    
+    return InvitationResponse(
+        token=invitation_token,
+        expires_at=expires_at.isoformat(),
+        message="Invitation link generated successfully. Valid for 24 hours.",
+    )