fix(cli): replace *> with 2>&1 | Out-File in install.ps1

The `*>` redirection operator on native commands can cause a .NET
`InvalidOperationException` when `StandardOutputEncoding` is set but
`RedirectStandardOutput` is not. This happens interactively (real
console attached) but not in CI (no console). Using `2>&1 | Out-File`
goes through the standard pipeline path which correctly sets both.

Also adds a PowerShell 7.6 CI test job for regression coverage.

Closes #1019

Author: fengmk2

.github/workflows/test-standalone-install.yml

@@ -474,6 +474,99 @@ jobs:
           vp upgrade --rollback
           vp --version
 
+  test-install-ps1-v76:
+    name: Test install.ps1 (Windows x64, PowerShell 7.6)
+    runs-on: windows-latest
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Install PowerShell 7.6
+        shell: pwsh
+        run: |
+          dotnet tool install --global PowerShell --version 7.6.0
+
+      - name: Assert PowerShell 7.6.x
+        shell: pwsh
+        run: |
+          $pwsh76 = "$env:USERPROFILE\.dotnet\tools\pwsh.exe"
+          $ver = & $pwsh76 -NoProfile -Command '$PSVersionTable.PSVersion.ToString()'
+          Write-Host "PowerShell version: $ver"
+          if (-not $ver.StartsWith("7.6")) {
+            Write-Error "Expected PowerShell 7.6.x but got $ver"
+            exit 1
+          }
+
+      - name: Run install.ps1 via iex (reproduces #1019)
+        shell: pwsh
+        run: |
+          $pwsh76 = "$env:USERPROFILE\.dotnet\tools\pwsh.exe"
+          & $pwsh76 -NoProfile -Command "Get-Content ./packages/cli/install.ps1 -Raw | Invoke-Expression"
+
+      - name: Set PATH
+        shell: bash
+        run: |
+          echo "$USERPROFILE\.vite-plus\bin" >> $GITHUB_PATH
+
+      - name: Verify installation
+        shell: pwsh
+        working-directory: ${{ runner.temp }}
+        run: |
+          $pwsh76 = "$env:USERPROFILE\.dotnet\tools\pwsh.exe"
+          & $pwsh76 -NoProfile -Command {
+            Write-Host "PATH: $env:Path"
+            vp --version
+            vp --help
+            vp create vite --no-interactive --no-agent -- hello --no-interactive -t vanilla
+            cd hello
+            vp run build
+            vp --version
+          }
+
+      - name: Verify bin setup
+        shell: pwsh
+        run: |
+          $pwsh76 = "$env:USERPROFILE\.dotnet\tools\pwsh.exe"
+          & $pwsh76 -NoProfile -Command {
+            $binPath = "$env:USERPROFILE\.vite-plus\bin"
+            Get-ChildItem -Force $binPath
+            if (-not (Test-Path $binPath)) {
+              Write-Error "Bin directory not found: $binPath"
+              exit 1
+            }
+
+            $expectedShims = @("node.exe", "npm.exe", "npx.exe")
+            foreach ($shim in $expectedShims) {
+              $shimFile = Join-Path $binPath $shim
+              if (-not (Test-Path $shimFile)) {
+                Write-Error "Shim not found: $shimFile"
+                exit 1
+              }
+              Write-Host "Found shim: $shimFile"
+            }
+            where.exe node
+            where.exe npm
+            where.exe npx
+            where.exe vp
+
+            $env:Path = "$env:USERPROFILE\.vite-plus\bin;$env:Path"
+            vp env doctor
+            vp env run --node 24 -- node -p "process.versions"
+          }
+
+      - name: Verify upgrade
+        shell: pwsh
+        run: |
+          $pwsh76 = "$env:USERPROFILE\.dotnet\tools\pwsh.exe"
+          & $pwsh76 -NoProfile -Command {
+            vp upgrade --check
+            vp upgrade 0.1.14-alpha.1
+            vp --version
+            vp upgrade --rollback
+            vp --version
+          }
+
   test-install-ps1:
     name: Test install.ps1 (Windows x64)
     runs-on: windows-latest

packages/cli/install.ps1

@@ -375,7 +375,7 @@ function Main {
         Push-Location $VersionDir
         try {
             $env:CI = "true"
-            & "$BinDir\vp.exe" install --silent *> $installLog
+            & "$BinDir\vp.exe" install --silent 2>&1 | Out-File $installLog
             if ($LASTEXITCODE -ne 0) {
                 Write-Host "error: Failed to install dependencies. See log for details: $installLog" -ForegroundColor Red
                 exit 1