fix: WxMpConfig AES Key 硬编码导致微信事件解密失败，FaultRecord 日期序列化修复

- WxMpConfig.setAesKey 从硬编码字面量 "aeskey" 改为读取配置值 this.aeskey
- 此 bug 导致所有微信推送事件（关注/取消关注/扫码）无法解密，故障订阅二维码绑定完全失效
- FaultRecord 三个日期字段添加 @JsonFormat 注解修复前端 NaN 显示

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

car-wash-admin/src/main/java/com/kym/admin/config/WxMpConfig.java

@@ -31,7 +31,7 @@ public class WxMpConfig {
         configStorage.setAppId(appid);
         configStorage.setSecret(secret);
         configStorage.setToken(token);
-        configStorage.setAesKey("aeskey");
+        configStorage.setAesKey(aeskey);
         service.addConfigStorage("MP", configStorage);
         return service;
     }

car-wash-entity/src/main/java/com/kym/entity/FaultRecord.java

@@ -1,6 +1,7 @@
 package com.kym.entity;
 
 import com.baomidou.mybatisplus.annotation.TableName;
+import com.fasterxml.jackson.annotation.JsonFormat;
 import lombok.Getter;
 import lombok.Setter;
 import lombok.experimental.Accessors;
@@ -44,6 +45,7 @@ public class FaultRecord extends BaseEntity<FaultRecord> {
     /**
      * 故障发生时间
      */
+    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")
     private LocalDateTime faultTime;
 
     /**
@@ -59,6 +61,7 @@ public class FaultRecord extends BaseEntity<FaultRecord> {
     /**
      * 通知发送时间
      */
+    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")
     private LocalDateTime notifyTime;
 
     /**
@@ -69,5 +72,6 @@ public class FaultRecord extends BaseEntity<FaultRecord> {
     /**
      * 恢复时间
      */
+    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm:ss", timezone = "GMT+8")
     private LocalDateTime recoverTime;
 }

car-wash-miniapp/src/main/java/com/kym/miniapp/config/WxMpConfig.java

@@ -31,7 +31,7 @@ public class WxMpConfig {
         configStorage.setAppId(appid);
         configStorage.setSecret(secret);
         configStorage.setToken(token);
-        configStorage.setAesKey("aeskey");
+        configStorage.setAesKey(aeskey);
         service.addConfigStorage("MP", configStorage);
         return service;
     }