补充前端交互边界注释

resources/js/chat-room/preferences-status.js

@@ -15,6 +15,7 @@ let blockMenuEventsBound = false;
  * @returns {{blocked_system_senders:string[],sound_muted:boolean}}
  */
 export function normalizeChatPreferences(raw, blockableSystemSenders = BLOCKABLE_SYSTEM_SENDERS) {
+    // 服务端或旧本地缓存可能包含已下架发送者，规整时只保留当前白名单。
     const blocked = Array.isArray(raw?.blocked_system_senders)
         ? raw.blocked_system_senders.filter((sender) => blockableSystemSenders.includes(sender))
         : [];
@@ -317,6 +318,7 @@ export function bindBlockMenuControls() {
  * @returns {boolean}
  */
 export function shouldMigrateLocalChatPreferences(serverPreferences, localBlockedSenders, localMuted) {
+    // 只有服务端尚无偏好时才迁移旧本地设置，避免覆盖已同步的账号配置。
     const hasServerPreferences = (serverPreferences?.blocked_system_senders || []).length > 0
         || Boolean(serverPreferences?.sound_muted);