fix: repair incomplete backend environment on start

scripts/one_click_start.ps1

@@ -54,15 +54,22 @@ $GpuPython = Join-Path $Root ".venv_paddle_gpu\Scripts\python.exe"
 $ImportCode = "import ultralytics, paddleocr, paddlex, cv2, PIL, numpy"
 
 $Ready = $false
+$SelectedPython = ""
 if ($Selected -eq "gpu") {
+    $SelectedPython = $GpuPython
     $Ready = Test-PythonImports $GpuPython $ImportCode
 } else {
+    $SelectedPython = $CpuPython
     $Ready = Test-PythonImports $CpuPython $ImportCode
 }
 
 if (-not $Ready) {
     Write-Host "Backend environment is missing or incomplete. Installing $Selected environment..."
     $argsList = @("-Target", $Selected)
+    if ($SelectedPython -and (Test-Path $SelectedPython)) {
+        Write-Host "Existing backend environment failed import checks. Recreating it..."
+        $argsList += "-Recreate"
+    }
     foreach ($arg in $PipArg) {
         $argsList += "-PipArg"
         $argsList += $arg

scripts/start_backend.ps1

@@ -40,7 +40,7 @@ function Test-BackendMainPython {
     $ErrFile = [System.IO.Path]::GetTempFileName()
     try {
         $Proc = Start-Process -FilePath $PythonPath `
-            -ArgumentList @("-c", "import ultralytics") `
+            -ArgumentList @("-c", "import ultralytics, PIL, cv2, numpy") `
             -NoNewWindow `
             -Wait `
             -PassThru `

start-backend.cmd

@@ -2,5 +2,5 @@
 chcp 65001 >nul
 cd /d "%~dp0"
 echo Starting GLM Coding Helper backend...
-powershell -NoProfile -ExecutionPolicy Bypass -File "scripts\start_backend.ps1" -Mode cpu -Port 8888
+powershell -NoProfile -ExecutionPolicy Bypass -File "scripts\one_click_start.ps1" -Target cpu -Port 8888
 pause