feat: add isolated utility export modes

controller/config.py

@@ -65,6 +65,7 @@ class DownloadConfig:
     max_height: int = 1080
     export_directory: Path = Path("exports")
     export_max_height: int = 1080
+    export_max_workers: int = 1
     max_queued_exports: int = 20
 
 
@@ -186,6 +187,9 @@ def _relative_directory(value: Any, name: str) -> Path:
         or "\\" in text
     ):
         raise ConfigError(f"{name} must be a safe relative directory")
+    reserved_roots = {f"slot{slot}" for slot in SLOT_IDS} | {".controller-trash"}
+    if path.parts[0].casefold() in reserved_roots:
+        raise ConfigError(f"{name} must not overlap Controller slot storage")
     return path
 
 
@@ -302,6 +306,11 @@ def load_config(
             downloads_raw.get("export_max_height", 1080),
             "downloads.export_max_height",
         ),
+        export_max_workers=_integer(
+            downloads_raw.get("export_max_workers", 1),
+            "downloads.export_max_workers",
+            maximum=10,
+        ),
         max_queued_exports=_integer(
             downloads_raw.get("max_queued_exports", 20),
             "downloads.max_queued_exports",