首次提交：脑晴测 H5 项目

包含前端源码、预构建产物（dist/）、零依赖 Node.js 服务器（server.mjs）、
Cloudflare Worker 版本（worker/）、部署文档（DEPLOY.md）和交接文档。

技术总监可直接 clone 后运行 node server.mjs 启动，无需安装 React 或 build。
DEEPSEEK_API_KEY 通过环境变量注入，未纳入仓库。

brain-h5/scripts/extract-video-frames.ps1

@@ -0,0 +1,122 @@
+param(
+  [Parameter(Mandatory = $true)]
+  [string]$VideoPath,
+
+  [Parameter(Mandatory = $true)]
+  [string]$OutputDirectory,
+
+  [int]$FrameCount = 12,
+
+  [double]$StartSeconds = 0,
+
+  [double]$EndSeconds = -1
+)
+
+$ErrorActionPreference = "Stop"
+Add-Type -AssemblyName PresentationCore
+Add-Type -AssemblyName WindowsBase
+
+function Invoke-DispatcherWait {
+  param([int]$Milliseconds)
+
+  $frame = [System.Windows.Threading.DispatcherFrame]::new()
+  $timer = [System.Windows.Threading.DispatcherTimer]::new(
+    [System.Windows.Threading.DispatcherPriority]::Background
+  )
+  $timer.Interval = [TimeSpan]::FromMilliseconds($Milliseconds)
+  $timer.Add_Tick({
+    $timer.Stop()
+    $frame.Continue = $false
+  })
+  $timer.Start()
+  [System.Windows.Threading.Dispatcher]::PushFrame($frame)
+}
+
+$resolvedVideo = (Resolve-Path -LiteralPath $VideoPath).Path
+$resolvedOutput = [System.IO.Path]::GetFullPath($OutputDirectory)
+[System.IO.Directory]::CreateDirectory($resolvedOutput) | Out-Null
+
+$player = [System.Windows.Media.MediaPlayer]::new()
+$player.ScrubbingEnabled = $true
+$player.Open([Uri]::new($resolvedVideo))
+$player.Play()
+
+for ($attempt = 0; $attempt -lt 100 -and $player.NaturalVideoWidth -eq 0; $attempt++) {
+  Invoke-DispatcherWait -Milliseconds 100
+}
+
+if ($player.NaturalVideoWidth -eq 0 -or -not $player.NaturalDuration.HasTimeSpan) {
+  $player.Close()
+  throw "Unable to decode video: $resolvedVideo"
+}
+
+$width = $player.NaturalVideoWidth
+$height = $player.NaturalVideoHeight
+$duration = $player.NaturalDuration.TimeSpan.TotalSeconds
+$rangeStart = [Math]::Min([Math]::Max($StartSeconds, 0), $duration)
+$rangeEnd = if ($EndSeconds -lt 0) {
+  $duration
+} else {
+  [Math]::Min([Math]::Max($EndSeconds, $rangeStart), $duration)
+}
+$metadata = [ordered]@{
+  path = $resolvedVideo
+  width = $width
+  height = $height
+  durationSeconds = [Math]::Round($duration, 3)
+  frames = @()
+}
+
+$player.Stop()
+$player.Position = [TimeSpan]::Zero
+$player.SpeedRatio = 16
+$player.Play()
+
+for ($index = 0; $index -lt $FrameCount; $index++) {
+  $ratio = if ($FrameCount -eq 1) { 0.5 } else { $index / ($FrameCount - 1) }
+  $seconds = $rangeStart + (($rangeEnd - $rangeStart) * $ratio)
+  $seconds = [Math]::Min([Math]::Max($seconds, 0), [Math]::Max($duration - 0.08, 0))
+  $deadline = [DateTime]::UtcNow.AddSeconds(45)
+  while ($player.Position.TotalSeconds -lt $seconds -and [DateTime]::UtcNow -lt $deadline) {
+    Invoke-DispatcherWait -Milliseconds 40
+  }
+  Invoke-DispatcherWait -Milliseconds 80
+
+  $visual = [System.Windows.Media.DrawingVisual]::new()
+  $context = $visual.RenderOpen()
+  $context.DrawVideo(
+    $player,
+    [Windows.Rect]::new(0, 0, $width, $height)
+  )
+  $context.Close()
+
+  $bitmap = [System.Windows.Media.Imaging.RenderTargetBitmap]::new(
+    $width,
+    $height,
+    96,
+    96,
+    [System.Windows.Media.PixelFormats]::Pbgra32
+  )
+  $bitmap.Render($visual)
+
+  $milliseconds = [long][Math]::Round($seconds * 1000)
+  $fileName = "frame-{0:D2}-{1:D6}ms.png" -f ([int]($index + 1)), $milliseconds
+  $filePath = Join-Path $resolvedOutput $fileName
+  $encoder = [System.Windows.Media.Imaging.PngBitmapEncoder]::new()
+  $encoder.Frames.Add([System.Windows.Media.Imaging.BitmapFrame]::Create($bitmap))
+  $stream = [System.IO.File]::Open($filePath, [System.IO.FileMode]::Create)
+  try {
+    $encoder.Save($stream)
+  } finally {
+    $stream.Dispose()
+  }
+
+  $metadata.frames += [ordered]@{
+    file = $fileName
+    seconds = [Math]::Round($seconds, 3)
+    actualSeconds = [Math]::Round($player.Position.TotalSeconds, 3)
+  }
+}
+
+$player.Close()
+$metadata | ConvertTo-Json -Depth 4