fix(security): F23 (Astra P1) — DB-weiter Restore nur noch fuer System-Admins

Vorher: POST /api/v1/backups/{id}/restore war ueber automation:admin
eines Mandanten erreichbar — der Restore bearbeitet aber die GESAMTE
geteilte Datenbank ohne Mandantenfilter. Ein Tenant-Admin haette den
Zustand aller Mandanten ueberschreiben koennen.

Fix: Restore-Route auf require_admin umgestellt (echter System-Admin:
is_system_admin oder *:* via RBAC). Listen/Erstellen/Loeschen von
Backups bleibt mandantenbezogen auf automation:admin.

Abnahme (Astra): Ein Tenant-Admin kann keinen Gesamtrestore ausloesen —
erfuellt (Route-Introspektions-Tests pinnen die Verdrahtung).

Tests: test_s1_security_guards.py 12/12 (2 neue F23-Tests: restore nutzt
require_admin, restore nutzt NICHT require_permission).

tests/test_s1_security_guards.py

@@ -221,3 +221,45 @@ class TestF03SessionRevocation:
         assert _rejects("invited") is True
         # active membership → allow
         assert _rejects("active") is False
+
+
+@pytest.mark.asyncio
+class TestF23RestoreRequiresSystemAdmin:
+    """F23 (Astra P1): a full-database restore is a GLOBAL operations
+    action — a tenant admin (automation:admin) must not be able to
+    trigger it. Route introspection pins the dependency wiring.
+    """
+
+    def _find_restore_route(self):
+        """Find the POST /{backup_id}/restore route on the backups router."""
+        from app.routes.backups import router
+
+        for route in router.routes:
+            if "restore" in getattr(route, "path", ""):
+                return route
+        return None
+
+    async def test_restore_route_uses_require_admin(self):
+        from app.deps import require_admin
+
+        route = self._find_restore_route()
+        assert route is not None, "restore route not found"
+        deps = list(getattr(route, "dependencies", []))
+        assert any(getattr(d, "dependency", None) is require_admin for d in deps), (
+            "F23: restore route must depend on require_admin (system admin), "
+            "not automation:admin"
+        )
+
+    async def test_restore_route_not_tenant_admin(self):
+        from app.deps import require_permission
+
+        route = self._find_restore_route()
+        assert route is not None
+        deps = list(getattr(route, "dependencies", []))
+        for d in deps:
+            dep_fn = getattr(d, "dependency", None)
+            assert dep_fn is not require_permission, (
+                "F23: restore route must not use require_permission("
+                "automation:admin) — a tenant admin must not trigger a "
+                "full-database restore"
+            )