refactor: auto-init guest chat quota on first read, clean up logs

- Remove unused `quotaWarningThreshold` and `warningThreshold` getter from `GuestChatQuota` DTO
- Apply get-or-init pattern in `ChatStorage.getGuestDailyChatQuota` and `getGuestTotalQuota`: when no existing value, initialize with DTO defaults (`threshold` = max per day, `totalQuotaDefault`) and return the seeded data
- Fall back to original `null` result if initialization write fails
- Consolidate logging strategy: drop per-actor trace logs in `chat-machine.ts`, keep business-decision logs in 3 assign actions, move all actor ENTRY/API/DONE chains to `chat-machine.actors.ts` and helper load logs to `chat-machine.helpers.ts`

src/data/dto/chat/guest_chat_quota.ts

@@ -11,9 +11,7 @@ export class GuestChatQuota {
   // 静态常量
   static readonly maxQuotaPerDay = 40;
   static readonly maxQuotaPerDayTest = 4;
-  static readonly quotaWarningThreshold = 20;
 
-  static readonly quotaWarningThresholdTest = 2;
   static readonly defaultTotalQuota = 50;
   static readonly defaultTotalQuotaDev = 5;
   static readonly quotaExhausted = 0;
@@ -49,15 +47,6 @@ export class GuestChatQuota {
     return process.env.NODE_ENV !== "production";
   }
 
-  /**
-   * 获取当前环境的配额警告阈值
-   */
-  static get warningThreshold(): number {
-    return GuestChatQuota.isDevelopment
-      ? GuestChatQuota.quotaWarningThresholdTest
-      : GuestChatQuota.quotaWarningThreshold;
-  }
-
   /**
    * 获取当前环境的每日最大配额
    */