fix: container volumes

progression_backend/workshop.py

@@ -116,6 +116,20 @@ class SteamCmdRunner:
     def available(self) -> bool:
         return self.executable_path() is not None
 
+    def ensure_workshop_writable(self) -> None:
+        workshop_dir = self.content_dir.parent.parent
+        try:
+            workshop_dir.mkdir(parents=True, exist_ok=True)
+            self.content_dir.mkdir(parents=True, exist_ok=True)
+            probe = workshop_dir / ".progression-write-test"
+            probe.write_text("ok", encoding="utf-8")
+            probe.unlink()
+        except OSError as error:
+            raise PermissionError(
+                f"SteamCMD Workshop directory is not writable: {workshop_dir}. "
+                "Check the container volume ownership."
+            ) from error
+
     def run_batch(
         self,
         workshop_ids: list[str],
@@ -129,6 +143,7 @@ class SteamCmdRunner:
         invalid = [item for item in workshop_ids if not item.isdigit()]
         if invalid:
             raise ValueError(f"Invalid Workshop ids: {', '.join(invalid)}")
+        self.ensure_workshop_writable()
 
         command = [executable, "+login", "anonymous"]
         for workshop_id in workshop_ids: