fix: use app_config map type instead of legacy addon_config (#876)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

Author: Koenkk

zigbee2mqtt-edge/config.json

@@ -31,7 +31,7 @@
       "path": "/config"
     },
     {
-      "type": "addon_config",
+      "type": "app_config",
       "read_only": false,
       "path": "/addon_config"
     },

zigbee2mqtt/config.json

@@ -34,7 +34,7 @@
       "path": "/config"
     },
     {
-      "type": "addon_config",
+      "type": "app_config",
       "read_only": false,
       "path": "/addon_config"
     },