sync(theme-4): 同步 main 最新 API/Admin 与玩家端逻辑

从 main 同步站内信手动发送、媒体库选择、列表子路由重构等 API/Admin 改动；玩家端仅合并 ADMIN_CUSTOM 富文本、消息预览与充值截图压缩逻辑，保留 theme-4 样式。

apps/api/src/shared/config/system-config.service.ts

@@ -263,4 +263,31 @@ export class SystemConfigService {
     }
     return this.getInboxNotifySettings();
   }
+
+  async getDepositScreenshotCleanupConfig(): Promise<{ enabled: boolean; keepDays: number }> {
+    const enabled = await this.getBoolean('deposit.cleanup.enabled', false);
+    const keepDays = await this.getInt('deposit.cleanup.keep_days', 180);
+    return { enabled, keepDays };
+  }
+
+  async updateDepositScreenshotCleanupConfig(data: { enabled?: boolean; keepDays?: number }) {
+    if (data.enabled !== undefined) {
+      await this.setBoolean(
+        'deposit.cleanup.enabled',
+        data.enabled,
+        '是否开启定时清理充值截图',
+      );
+    }
+    if (data.keepDays !== undefined) {
+      if (!Number.isInteger(data.keepDays) || data.keepDays <= 0) {
+        throw new Error('keepDays must be a positive integer');
+      }
+      await this.setInt(
+        'deposit.cleanup.keep_days',
+        data.keepDays,
+        '充值截图保留天数',
+      );
+    }
+    return this.getDepositScreenshotCleanupConfig();
+  }
 }