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/auth.py

@@ -18,6 +18,7 @@ from app.models.user import User
 from app.models.subject import Subject
 from app.schemas.auth import LoginRequest, RegisterRequest, TokenResponse
 from app.schemas.user import UserOut
+from app.utils.client_ip import client_ip
 from app.utils.ntfy import notify
 
 router = APIRouter(prefix="/api/auth", tags=["auth"])
@@ -59,7 +60,7 @@ async def register(body: RegisterRequest, response: Response, request: Request,
     refresh = create_refresh_token({"sub": str(user.id)})
     response.set_cookie(REFRESH_COOKIE, refresh, **COOKIE_OPTS)
 
-    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 New User Registered",
@@ -83,7 +84,7 @@ async def login(body: LoginRequest, response: Response, request: Request, db: As
         raise HTTPException(status_code=401, detail="Invalid credentials")
 
     now = datetime.now(timezone.utc).replace(tzinfo=None)
-    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")
 
     if user.locked_until and user.locked_until > now: