chore: merge integ configs root and switch folders

The configs root place joins roms and emulator folders in the split
handed directories, and RetroBat's portable folder table keeps both
sides. Batocera, KNULLI and RetroBat records regenerated.

scripts/common.py

@@ -2882,7 +2882,8 @@ OUTSIDE_BIOS_FOLDER = "outside_bios_folder"
 # describes. Each is located by the registry entry <root>_directory.
 ROMS_ROOT = "roms"
 EMULATORS_ROOT = "emulators"
-OUTER_ROOTS = (ROMS_ROOT, EMULATORS_ROOT)
+CONFIGS_ROOT = "configs"
+OUTER_ROOTS = (ROMS_ROOT, EMULATORS_ROOT, CONFIGS_ROOT)
 
 
 def outer_layout(config: dict, root: str) -> dict | None:
@@ -2915,6 +2916,15 @@ def outer_layout(config: dict, root: str) -> dict | None:
         return {"path": str(path), "install_prefix": "" if inside == "." else inside}
     if root == EMULATORS_ROOT:
         return config.get("emulators_directory") or None
+    if root == CONFIGS_ROOT:
+        # The frontend's configs folder, as its path code builds it
+        # (configs_root, Batocera's batoceraPaths CONFIGS).
+        found = config.get("configs_root") or {}
+        base = str(config.get("base_destination") or "")
+        if not (found.get("path") and found.get("from_bios") and base):
+            return None
+        return {"path": str(found["path"]), "from_bios": str(found["from_bios"]),
+                "bios_folder": base}
     return None