fix: keep RomM files where its player reads them

RomM lists a platform's firmware folder without descending (base_handler.py:1002, recursive=False) and EmulatorJS writes the chosen file, or each zip member, under its bare name. 543 files of the RomM pack sat below a folder where no core could read them. The registry now marks RomM's folder flat, and such files are omitted with the reason below_platform_folder in the manifest and the installer.

scripts/generate_pack.py

@@ -3859,7 +3859,7 @@ def _record_unplaceable(unplaceable: list[dict], record_omission: Callable[...,
     for u in unplaceable:
         record_omission(
             u.get("path") or u.get("name", ""), u, u.get("system") or "",
-            "no_platform_slug", [u.get("emulator", "")],
+            u.get("unplaceable", "no_platform_slug"), [u.get("emulator", "")],
         )
 
 

scripts/packextras.py

@@ -678,6 +678,7 @@ class ExtraPlacement:
         self.slug_based, self.sys_to_slug = _detect_slug_structure(config)
         self.platform_systems = set(config.get("systems", {}).keys())
         self.native_systems = native_slug_systems(config)
+        self.flat = bool(config.get("firmware_folder_flat"))
         self.norm_map = (
             {_norm_system_id(sid): sid for sid in self.platform_systems}
             if self.slug_based
@@ -697,11 +698,15 @@ class ExtraPlacement:
                 entry, self.profiles, self.platform_systems, self.norm_map,
                 self.sys_to_slug, self.native_systems,
             )
-            if not slug:
+            if not slug or self.nested(dest):
                 return None
             dest = f"{slug}/{dest}"
         return dest, (f"{self.prefix}/{dest}" if self.prefix else dest)
 
+    def nested(self, dest: str) -> bool:
+        """True when the file would sit below a folder the frontend lists flat."""
+        return self.slug_based and self.flat and "/" in dest
+
 
 def _collect_emulator_extras(
     config: dict,
@@ -802,7 +807,10 @@ def _collect_emulator_extras(
             continue
         if placed is None:
             if unplaceable is not None:
-                unplaceable.append(u)
+                unplaceable.append(
+                    {**u, "unplaceable": "below_platform_folder"}
+                    if placement.nested(dest) else u
+                )
             continue
         dest, full_dest = placed
         if claimants is not None: