feat: Szenario per GUI löschen, Name System-Ist reserviert (A11-T1)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

finance/tests/test_crud_api.py

@@ -1,6 +1,8 @@
 from datetime import date, timedelta
 from decimal import Decimal
 
+import pytest
+
 from app.models.tables import Account, Transaction
 from app.services.balances import account_balance
 
@@ -294,3 +296,25 @@ def test_scenario_planned_patch(client, db):
     r = client.patch(f"/api/scenarios/{other['id']}/planned/{p['id']}", headers=H, json={
         "name": "x", "amount": "1.00", "due": "2026-08-15"})
     assert r.status_code == 404
+
+
+@pytest.mark.parametrize("name", ["System-Ist", "system-ist", "  System-Ist  ", "SYSTEM-IST"])
+def test_szenario_name_system_ist_ist_reserviert_post(client, name):
+    r = client.post("/api/scenarios", json={"name": name}, headers=H)
+    assert r.status_code == 422
+    assert "reserviert" in r.json()["detail"]
+
+
+def test_szenario_name_system_ist_ist_reserviert_patch(client):
+    sid = client.post("/api/scenarios", json={"name": "Normal"}, headers=H).json()["id"]
+    r = client.patch(f"/api/scenarios/{sid}", json={"name": "System-Ist"}, headers=H)
+    assert r.status_code == 422
+    assert "reserviert" in r.json()["detail"]
+    # Andere Felder ohne Namensänderung bleiben erlaubt.
+    r = client.patch(f"/api/scenarios/{sid}", json={"description": "x"}, headers=H)
+    assert r.status_code == 200
+
+
+def test_szenario_normale_namen_weiter_erlaubt(client):
+    assert client.post("/api/scenarios", json={"name": "Ist-Zustand plus"},
+                       headers=H).status_code == 201