feat(sdk): 绑定时上报设备 log 到 update-metadata 并内聚双层绑定

- bind(userId:) 内聚为硬绑 + getVersion + 软绑 + updateMetadata 一次原子调用,
  软绑失败自动硬解绑回滚 + 清状态;集成方无需感知双层绑定
- fetchLatestFirmware 简化为对账上报 + checkUpgrade 两步,不再重复软绑
- VersionInfo 增加 log: [String: Any]?,走 JSONSerialization 解析(放弃 Codable);
  SDK 暴露只读 versionLog,断连/解绑/软绑回滚时清空
- ShipmentSnDeviceService 新增 updateMetadata(sn:data:),抽出 performPOST
  共享 HTTP 编排,新增 postAnyJSON 支持 [String: Any] body
- 老固件不返回 log → versionLog == nil → 自动跳过 updateMetadata,前向兼容

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Sources/DuooomiBleSDK/DuooomiBleSDK.swift

@@ -41,6 +41,10 @@ public final class DuooomiBleSDK: NSObject {
         didSet { notifyMain { self.delegate?.sdk(self, didUpdateVersion: self.version) } }
     }
 
+    /// 设备返回的 `log` 字段（任意 JSON 对象）。`getVersion` 成功时写入，断连/解绑时清空。
+    /// `fetchLatestFirmware` 软绑后透传给 shipment-sn `update-metadata`，集成方一般无需直接读。
+    public internal(set) var versionLog: [String: Any]?
+
     public internal(set) var isActivated: Bool = false {
         didSet {
             guard isActivated != oldValue else { return }
@@ -174,6 +178,7 @@ public final class DuooomiBleSDK: NSObject {
             self.connectedDevice = nil
             self.deviceInfo = nil
             self.version = ""
+            self.versionLog = nil
             self.isActivated = false
             self.btState = .disconnected
             self.protocolService.stopListening()