refactor(modmail): centralize config into single /modmail config panel

- Remove 5 redundant commands (setup, addcategory, removecategory, enable, disable)
- Single /modmail config opens interactive Components V2 panel
- Channel select for ticket category, role select for staff, channel select for logs
- Toggle enable/disable button
- Categories sub-panel: add via modal, remove via select
- Fix lint (unused imports/vars, contextlib.suppress) + ruff format

utils/modmail_config.py

@@ -1,5 +1,4 @@
 import json
-from pathlib import Path
 
 from config import DATA_DIR
 
@@ -32,6 +31,12 @@ def get_config() -> dict:
     return _load()
 
 
+def set_guild_id(guild_id: int):
+    data = _load()
+    data["guild_id"] = guild_id
+    _save(data)
+
+
 def set_enabled(guild_id: int, enabled: bool):
     data = _load()
     data["enabled"] = enabled