Schritt 1: Fundament der Lebensmittel-Lagerverwaltung (Pantry)

Backend (FastAPI + PostgreSQL): Chargen mit MHD, FEFO-Auslagern,
Einheiten-Umrechnung (Stueck/g/ml + Packungen), Open-Food-Facts-Lookup
mit lokalem Fallback, JWT-Auth mit Rollen (Admin/Nutzer), erster Admin
beim Setup, Einkaufsliste, Ablaufwarnung, Lagerorte, pytest fuer FEFO.

Web-UI (React/Vite): Login, Dashboard, Ein-/Auslagern, Produkte,
Lagerorte, Benutzerverwaltung, Einkaufsliste - rollenabhaengig.

Deploy: docker-compose + install.sh (Docker-Autoinstall, Secrets),
README und Roadmap fuer Schritt 2 (iOS) und Schritt 3.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/app/routers/settings.py

@@ -0,0 +1,49 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy.orm import Session
+
+from ..config import get_settings
+from ..database import get_db
+from ..deps import get_current_user, require_admin
+from ..models import Setting, User
+from ..schemas import SettingOut
+
+router = APIRouter(prefix="/settings", tags=["settings"])
+
+EXPIRY_WARNING_KEY = "expiry_warning_days"
+
+
+def get_expiry_warning_days(db: Session) -> int:
+    row = db.get(Setting, EXPIRY_WARNING_KEY)
+    if row is None:
+        return get_settings().expiry_warning_days_default
+    try:
+        return int(row.value)
+    except ValueError:
+        return get_settings().expiry_warning_days_default
+
+
+@router.get("", response_model=list[SettingOut])
+def list_settings(
+    db: Session = Depends(get_db), _: User = Depends(get_current_user)
+) -> list[SettingOut]:
+    rows = db.query(Setting).all()
+    known = {r.key: r.value for r in rows}
+    known.setdefault(EXPIRY_WARNING_KEY, str(get_expiry_warning_days(db)))
+    return [SettingOut(key=k, value=v) for k, v in known.items()]
+
+
+@router.put("/{key}", response_model=SettingOut)
+def set_setting(
+    key: str,
+    value: str,
+    db: Session = Depends(get_db),
+    _: User = Depends(require_admin),
+) -> SettingOut:
+    row = db.get(Setting, key)
+    if row is None:
+        row = Setting(key=key, value=value)
+        db.add(row)
+    else:
+        row.value = value
+    db.commit()
+    return SettingOut(key=key, value=value)