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_gui.py

@@ -483,3 +483,24 @@ def test_grafana_links_fallback_to_host_port_when_unset(client, monkeypatch):
         assert "fb.example.de" not in r.text
     finally:
         get_settings.cache_clear()
+
+
+def test_szenarien_seite_hat_loeschen_button(client, db):
+    client.post("/login", data={"username": "admin", "password": "geheim"})
+    sc = Scenario(name="Wegwerf", description="", include_recurring=True,
+                  include_planned=True)
+    db.add(sc)
+    db.commit()
+    r = client.get("/szenarien")
+    assert f'hx-delete="/api/scenarios/{sc.id}"' in r.text
+    assert 'Szenario „Wegwerf" mit allen Einträgen wirklich löschen?' in r.text
+
+
+def test_szenario_loeschen_roundtrip_gui(client, db):
+    client.post("/login", data={"username": "admin", "password": "geheim"})
+    sc = Scenario(name="Wegwerf-Roundtrip", description="", include_recurring=True,
+                  include_planned=True)
+    db.add(sc)
+    db.commit()
+    assert client.delete(f"/api/scenarios/{sc.id}", headers=H).status_code == 204
+    assert "Wegwerf-Roundtrip" not in client.get("/szenarien").text