feat: add isolated utility export modes

tests/test_config_contracts.py

@@ -84,6 +84,7 @@ class ConfigurationTests(unittest.TestCase):
         self.assertEqual(config.mqtt.router_echo_grace_seconds, 2.0)
         self.assertEqual(config.downloads.export_directory, Path("exports"))
         self.assertEqual(config.downloads.export_max_height, 1080)
+        self.assertEqual(config.downloads.export_max_workers, 1)
         self.assertEqual(config.downloads.max_queued_exports, 20)
 
     def test_documented_environment_overrides_apply(self):
@@ -190,9 +191,23 @@ class ConfigurationTests(unittest.TestCase):
                 with self.assertRaisesRegex(ConfigError, "safe relative directory"):
                     load_config(path, environ={})
 
+    def test_export_directory_cannot_overlap_player_slot_storage(self):
+        invalid = ("slot1", "SLOT10/exports", ".controller-trash/exports")
+        for value in invalid:
+            with self.subTest(value=value), tempfile.TemporaryDirectory() as directory:
+                path = Path(directory) / "config.yaml"
+                path.write_text(
+                    f"downloads:\n  export_directory: {value!r}\n",
+                    encoding="utf-8",
+                )
+                with self.assertRaisesRegex(ConfigError, "slot storage"):
+                    load_config(path, environ={})
+
     def test_export_limits_are_bounded_positive_integers(self):
         cases = (
             ("export_max_height", 0),
+            ("export_max_workers", 0),
+            ("export_max_workers", 11),
             ("max_queued_exports", 0),
             ("max_queued_exports", 1001),
         )