Fix MEDIUM findings from 2026-09-24 maintenance review

- Backend retries DB connection at startup (up to 180s) so host reboots
  no longer crash-loop it; add backend and frontend healthchecks
- Docker log rotation (json-file 10m x 3) on all services
- ntfy alerts use X-Real-IP (set by nginx after real_ip resolution)
  instead of the client-controlled first X-Forwarded-For entry
- Frontend build on Node 24 LTS with package-lock.json + npm ci;
  axios 1.20.0, vite 5.4.21
- README: backup/restore/rollback runbook, real-IP proxy trust notes
- Release-Notes/v1.1.md; version 1.1.0

Co-Authored-By: Claude Opus 5.5 <[email protected]>

backend/app/routers/admin.py

@@ -9,6 +9,7 @@ from app.auth.jwt import create_admin_token, create_access_token, hash_password
 from app.config import get_settings
 from app.dependencies import get_db, get_admin_user
 from app.models.user import User
+from app.utils.client_ip import client_ip
 from app.utils.ntfy import notify
 
 router = APIRouter(prefix="/api/admin", tags=["admin"])
@@ -23,7 +24,7 @@ async def admin_login(body: dict, request: Request):
         logger.warning("Failed super-admin login attempt for username=%s", username)
         raise HTTPException(status_code=status.HTTP_401_UNAUTHORIZED, detail="Invalid admin credentials")
     token = create_admin_token({"sub": "admin"})
-    ip = request.headers.get("X-Forwarded-For", request.client.host if request.client else "unknown").split(",")[0].strip()
+    ip = client_ip(request)
     ua = request.headers.get("User-Agent", "unknown")
     await notify(
         title="Homeschool Dashboard Super Admin Login",