feat(camera): 添加相机预览超时处理机制

- 引入 Handler 和 Looper 处理异步操作
- 实现预览超时检测功能，超时后自动执行拍照
- 在相机打开、关闭和出错时移除超时回调
- 开始预览时启动超时计时器，1秒后触发
- 执行拍照前移除所有待执行的超时回调
- 显示预览不可用时的用户提示信息

app/src/main/java/com/nova/brain/glass/ui/InspectionActivity.kt

@@ -2,6 +2,8 @@ package com.nova.brain.glass.ui
 
 import android.content.Intent
 import android.os.Environment
+import android.os.Handler
+import android.os.Looper
 import android.view.WindowManager
 import android.view.Surface
 import android.view.TextureView
@@ -43,6 +45,14 @@ class InspectionActivity :
     private var maxZoomLevel = 1
     private var previewStartAttempted = false
     private var previewSurface: Surface? = null
+    private val mainHandler = Handler(Looper.getMainLooper())
+    private val previewTimeoutRunnable = Runnable {
+        if (isPreviewActive || !isPreviewRequested) return@Runnable
+        LogHelper.d("Inspection preview timeout, fallback to direct takePhoto")
+        stopCameraPreview()
+        binding.hint.text = "预览不可用，直接拍照中，请稍后..."
+        takePhoto()
+    }
 
     private val listener = object : OfflineCmdListener {
         override fun onOfflineCmd(cmd: String) {
@@ -64,6 +74,7 @@ class InspectionActivity :
         override fun onCameraOpened(width: Int, height: Int) {
             LogHelper.d("Inspection preview onCameraOpened: ${width}x$height")
             isPreviewActive = true
+            mainHandler.removeCallbacks(previewTimeoutRunnable)
             currentZoomLevel = GlassMediaServiceHelper.getZoomLevel().coerceAtLeast(1)
             maxZoomLevel = GlassMediaServiceHelper.getMaxZoomLevel().coerceAtLeast(1)
             runOnUiThread {
@@ -77,6 +88,7 @@ class InspectionActivity :
         override fun onCameraClosed() {
             LogHelper.d("Inspection preview onCameraClosed")
             isPreviewActive = false
+            mainHandler.removeCallbacks(previewTimeoutRunnable)
             runOnUiThread {
                 binding.cameraPreviewContainer.visibility = View.GONE
                 binding.zoomText.visibility = View.GONE
@@ -86,6 +98,7 @@ class InspectionActivity :
         override fun onError(code: Int, message: String?) {
             LogHelper.d("Inspection preview onError: code=$code msg=$message")
             isPreviewActive = false
+            mainHandler.removeCallbacks(previewTimeoutRunnable)
             runOnUiThread {
                 binding.cameraPreviewContainer.visibility = View.GONE
                 binding.zoomText.visibility = View.GONE
@@ -208,11 +221,14 @@ class InspectionActivity :
         previewSurface?.release()
         previewSurface = Surface(surfaceTexture)
         LogHelper.d("Inspection startCameraPreview invoke startCameraShare, buffer=${width}x$height")
+        mainHandler.removeCallbacks(previewTimeoutRunnable)
+        mainHandler.postDelayed(previewTimeoutRunnable, 1000L)
         runCatching {
             GlassMediaServiceHelper.startCameraShare(previewSurface!!, cameraSurfaceCallback)
         }.onFailure {
             isPreviewRequested = false
             previewStartAttempted = false
+            mainHandler.removeCallbacks(previewTimeoutRunnable)
             previewSurface?.release()
             previewSurface = null
             binding.cameraPreviewContainer.visibility = View.GONE
@@ -227,6 +243,7 @@ class InspectionActivity :
         isPreviewRequested = false
         isPreviewActive = false
         previewStartAttempted = false
+        mainHandler.removeCallbacks(previewTimeoutRunnable)
         LogHelper.d("Inspection stopCameraPreview")
         runCatching {
             GlassMediaServiceHelper.stopCameraShare(cameraSurfaceCallback)