fix(device): 修复设备切换连接订阅累积与自动重连，连接后更新缓存

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

miniprogram/lefu/service.ts

@@ -94,6 +94,7 @@ class LeFuService {
 	 */
 	startScan(): void {
 		console.log(TAG, 'startScan()')
+		this._intentionalConnect = true
 		plugin.Blue.setDeviceSetting(DEVICE_SETTINGS)
 		this._subscribeBus()
 		plugin.Blue.start(DEVICE_SETTINGS.map(s => s.deviceName), false)
@@ -185,11 +186,9 @@ class LeFuService {
 				}
 				return
 			}
-			// 蓝牙就绪：如有缓存设备且非主动断开，尝试重连
+			// 蓝牙就绪：非主动操作（意外断开）且有缓存设备时自动重连，主动扫描/连接期间不重连
 			if (res === plugin.BLUE_STATE.READY) {
-				if (this._intentionalConnect) {
-					this._intentionalConnect = false
-				} else if (this._lastRawDevice && !this._activeProtocol) {
+				if (!this._intentionalConnect && this._lastRawDevice && !this._activeProtocol && this._onDevicesListCbs.size === 0) {
 					this._stopReconnectTimer()
 					wx.openBluetoothAdapter({
 						success: () => this.connect(this._lastRawDevice!),