Add FastAPI application, API endpoints, Celery workers, and Docker configuration

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

backend/app/api/v1/endpoints/admin.py

@@ -0,0 +1,36 @@
+"""Admin endpoints"""
+from fastapi import APIRouter, Depends
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy import select, func
+
+from app.core.database import get_db
+from app.core.deps import get_current_superuser
+from app.models.database_models import User, MailAccount, ProcessingRun
+
+router = APIRouter()
+
+
+@router.get("/stats")
+async def get_admin_stats(
+    current_user: User = Depends(get_current_superuser),
+    db: AsyncSession = Depends(get_db)
+):
+    """Get overall system statistics (admin only)"""
+    
+    # Count users
+    user_count = await db.execute(select(func.count(User.id)))
+    total_users = user_count.scalar()
+    
+    # Count accounts
+    account_count = await db.execute(select(func.count(MailAccount.id)))
+    total_accounts = account_count.scalar()
+    
+    # Count processing runs
+    run_count = await db.execute(select(func.count(ProcessingRun.id)))
+    total_runs = run_count.scalar()
+    
+    return {
+        "total_users": total_users,
+        "total_mail_accounts": total_accounts,
+        "total_processing_runs": total_runs
+    }