refactor: simplify codebase with unified patterns and reduced duplication

- unify ChatConfigService setters into generic setPermission method
- replace PermissionService switch statements with data-driven checkers map
- deduplicate config.ts callback handlers via loop-based registration (414→254 lines)
- extract shared updateChatCommands utility from role-add/role-delete
- add proper generics to chunk utility, fix mention loop indexing
- extract isHiddenAdmin helper and ANONYMOUS_ADMIN_ID constant in perms
- remove debug console.logs, standardize arrow exports and type imports
- add roleAdminPermission schema and migration

drizzle/meta/_journal.json

@@ -15,6 +15,13 @@
       "when": 1764313289570,
       "tag": "0001_legal_blob",
       "breakpoints": true
+    },
+    {
+      "idx": 2,
+      "version": "7",
+      "when": 1765468835132,
+      "tag": "0002_bored_stephen_strange",
+      "breakpoints": true
     }
   ]
 }