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/tests/test_fefo.py

@@ -0,0 +1,81 @@
+from datetime import date, timedelta
+
+import pytest
+
+from app.services.stock import StockError, check_in, check_out, current_stock
+
+
+def _checkin(db, product, qty, unit, best_before=None):
+    lot = check_in(db, product, qty, unit, best_before, None, None)
+    db.commit()
+    return lot
+
+
+def test_checkin_creates_lot_in_base_units(db, rice):
+    _checkin(db, rice, 3, "package")  # 1500 g
+    assert current_stock(db, rice.id) == 1500
+
+
+def test_checkout_partial_amount(db, rice):
+    _checkin(db, rice, 3, "package")  # 1500 g
+    check_out(db, rice, 200, "g", None)
+    db.commit()
+    assert current_stock(db, rice.id) == 1300
+
+
+def test_fefo_takes_earliest_expiry_first(db, rice):
+    soon = date.today() + timedelta(days=5)
+    later = date.today() + timedelta(days=60)
+    # Zuerst die später ablaufende Charge einlagern ...
+    _checkin(db, rice, 500, "g", best_before=later)
+    # ... dann die früher ablaufende.
+    _checkin(db, rice, 500, "g", best_before=soon)
+
+    check_out(db, rice, 400, "g", None)
+    db.commit()
+
+    # Die früh ablaufende Charge (soon) muss zuerst reduziert worden sein.
+    from app.models import Lot
+
+    lots = {l.best_before: l.quantity for l in db.query(Lot).all()}
+    assert lots[soon] == 100
+    assert lots[later] == 500
+
+
+def test_fefo_spans_multiple_lots_and_removes_empty(db, rice):
+    soon = date.today() + timedelta(days=5)
+    later = date.today() + timedelta(days=60)
+    _checkin(db, rice, 500, "g", best_before=soon)
+    _checkin(db, rice, 500, "g", best_before=later)
+
+    check_out(db, rice, 700, "g", None)  # 500 (soon) + 200 (later)
+    db.commit()
+
+    from app.models import Lot
+
+    lots = db.query(Lot).all()
+    assert len(lots) == 1  # leere soon-Charge entfernt
+    assert lots[0].best_before == later
+    assert lots[0].quantity == 300
+
+
+def test_null_best_before_is_last(db, rice):
+    dated = date.today() + timedelta(days=30)
+    _checkin(db, rice, 300, "g", best_before=None)
+    _checkin(db, rice, 300, "g", best_before=dated)
+
+    check_out(db, rice, 300, "g", None)
+    db.commit()
+
+    from app.models import Lot
+
+    remaining = db.query(Lot).all()
+    # Die datierte Charge wird zuerst genommen, die NULL-Charge bleibt.
+    assert len(remaining) == 1
+    assert remaining[0].best_before is None
+
+
+def test_checkout_more_than_available_raises(db, rice):
+    _checkin(db, rice, 100, "g")
+    with pytest.raises(StockError):
+        check_out(db, rice, 200, "g", None)