refactor: split HIGH_PRIO_STRUCTURE_PATH into STRUCTURE_PATH_A/B

Replace the single HIGH_PRIO_STRUCTURE_PATH config attribute with two
glob patterns (STRUCTURE_PATH_A = roms/*, STRUCTURE_PATH_B = */roms) and
update all call sites to detect Structure B via glob.glob, defaulting to
Structure A when no match is found.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

backend/config/config_manager.py

@@ -114,7 +114,8 @@ class Config:
     ROMS_FOLDER_NAME: str
     FIRMWARE_FOLDER_NAME: str
     SKIP_HASH_CALCULATION: bool
-    HIGH_PRIO_STRUCTURE_PATH: str
+    STRUCTURE_PATH_A: str
+    STRUCTURE_PATH_B: str
     EJS_DEBUG: bool
     EJS_CACHE_LIMIT: int | None
     EJS_DISABLE_AUTO_UNLOAD: bool
@@ -133,7 +134,8 @@ class Config:
 
     def __init__(self, **entries):
         self.__dict__.update(entries)
-        self.HIGH_PRIO_STRUCTURE_PATH = f"{LIBRARY_BASE_PATH}/{self.ROMS_FOLDER_NAME}"
+        self.STRUCTURE_PATH_A = f"{LIBRARY_BASE_PATH}/{self.ROMS_FOLDER_NAME}/*"
+        self.STRUCTURE_PATH_B = f"{LIBRARY_BASE_PATH}/*/{self.ROMS_FOLDER_NAME}"
 
 
 class ConfigManager:

backend/handler/filesystem/firmware_handler.py

@@ -1,4 +1,5 @@
 import binascii
+import glob
 import hashlib
 import os
 
@@ -17,9 +18,9 @@ class FSFirmwareHandler(FSHandler):
     def get_firmware_fs_structure(self, fs_slug: str) -> str:
         cnfg = cm.get_config()
         return (
-            f"{cnfg.FIRMWARE_FOLDER_NAME}/{fs_slug}"
-            if os.path.exists(cnfg.HIGH_PRIO_STRUCTURE_PATH)
-            else f"{fs_slug}/{cnfg.FIRMWARE_FOLDER_NAME}"
+            f"{fs_slug}/{cnfg.FIRMWARE_FOLDER_NAME}"
+            if glob.glob(cnfg.STRUCTURE_PATH_B)
+            else f"{cnfg.FIRMWARE_FOLDER_NAME}/{fs_slug}"
         )
 
     async def get_firmware(self, platform_fs_slug: str):

backend/handler/filesystem/platforms_handler.py

@@ -1,3 +1,4 @@
+import glob
 import os
 
 from anyio import Path as AnyioPath
@@ -62,20 +63,16 @@ class FSPlatformsHandler(FSHandler):
         cnfg = cm.get_config()
 
         # Fallback to config hint when detection is inconclusive
-        return (
-            cnfg.ROMS_FOLDER_NAME
-            if os.path.exists(cnfg.HIGH_PRIO_STRUCTURE_PATH)
-            else ""
-        )
+        return "" if glob.glob(cnfg.STRUCTURE_PATH_B) else cnfg.ROMS_FOLDER_NAME
 
     def get_platform_fs_structure(self, fs_slug: str) -> str:
         cnfg = cm.get_config()
 
         # Fallback to config hint when detection is inconclusive
         return (
-            f"{cnfg.ROMS_FOLDER_NAME}/{fs_slug}"
-            if os.path.exists(cnfg.HIGH_PRIO_STRUCTURE_PATH)
-            else f"{fs_slug}/{cnfg.ROMS_FOLDER_NAME}"
+            f"{fs_slug}/{cnfg.ROMS_FOLDER_NAME}"
+            if glob.glob(cnfg.STRUCTURE_PATH_B)
+            else f"{cnfg.ROMS_FOLDER_NAME}/{fs_slug}"
         )
 
     async def add_platform(self, fs_slug: str) -> None:

backend/handler/filesystem/roms_handler.py

@@ -1,6 +1,7 @@
 import binascii
 import bz2
 import fnmatch
+import glob
 import hashlib
 import os
 import re
@@ -313,9 +314,9 @@ class FSRomsHandler(FSHandler):
     def get_roms_fs_structure(self, fs_slug: str) -> str:
         cnfg = cm.get_config()
         return (
-            f"{cnfg.ROMS_FOLDER_NAME}/{fs_slug}"
-            if os.path.exists(cnfg.HIGH_PRIO_STRUCTURE_PATH)
-            else f"{fs_slug}/{cnfg.ROMS_FOLDER_NAME}"
+            f"{fs_slug}/{cnfg.ROMS_FOLDER_NAME}"
+            if glob.glob(cnfg.STRUCTURE_PATH_B)
+            else f"{cnfg.ROMS_FOLDER_NAME}/{fs_slug}"
         )
 
     def parse_tags(self, fs_name: str) -> ParsedTags:

backend/watcher.py

@@ -1,5 +1,6 @@
 import enum
 import fnmatch
+import glob
 import json
 import os
 from collections.abc import Sequence
@@ -49,7 +50,8 @@ sentry_sdk.init(
 )
 tracer = trace.get_tracer(__name__)
 
-structure_level = 2 if os.path.exists(cm.get_config().HIGH_PRIO_STRUCTURE_PATH) else 1
+_cfg = cm.get_config()
+structure_level = 1 if glob.glob(_cfg.STRUCTURE_PATH_B) else 2
 
 
 @enum.unique