docs: make powershell profile setup idempotent

Close #595

Author: aooohan

README.md

@@ -47,8 +47,15 @@ echo 'eval "$(vfox activate zsh)"' >> ~/.zshrc
 echo 'vfox activate fish | source' >> ~/.config/fish/config.fish
 
 # For PowerShell:
-if (-not (Test-Path -Path $PROFILE)) { New-Item -Type File -Path $PROFILE -Force }
-echo 'Invoke-Expression "$(vfox activate pwsh)"' >> $PROFILE
+if (-not (Test-Path -Path $PROFILE)) { New-Item -Type File -Path $PROFILE -Force | Out-Null }
+$vfoxLine = 'Invoke-Expression "$(vfox activate pwsh)"'
+$profileContent = Get-Content -Path $PROFILE -Raw
+if ($profileContent -notmatch [regex]::Escape($vfoxLine)) {
+  if ($profileContent.Length -gt 0 -and -not $profileContent.EndsWith("`r`n") -and -not $profileContent.EndsWith("`n")) {
+    Add-Content -Path $PROFILE -Value ""
+  }
+  Add-Content -Path $PROFILE -Value $vfoxLine
+}
 
 # For Clink:
 # 1. Install clink: https://github.com/chrisant996/clink/releases

README_CN.md

@@ -43,7 +43,15 @@ echo 'eval "$(vfox activate zsh)"' >> ~/.zshrc
 echo 'vfox activate fish | source' >> ~/.config/fish/config.fish
 
 # 对于 PowerShell
-if (-not (Test-Path -Path $PROFILE)) { New-Item -Type File -Path $PROFILE -Force }; Add-Content -Path $PROFILE -Value 'Invoke-Expression "$(vfox activate pwsh)"'
+if (-not (Test-Path -Path $PROFILE)) { New-Item -Type File -Path $PROFILE -Force | Out-Null }
+$vfoxLine = 'Invoke-Expression "$(vfox activate pwsh)"'
+$profileContent = Get-Content -Path $PROFILE -Raw
+if ($profileContent -notmatch [regex]::Escape($vfoxLine)) {
+  if ($profileContent.Length -gt 0 -and -not $profileContent.EndsWith("`r`n") -and -not $profileContent.EndsWith("`n")) {
+    Add-Content -Path $PROFILE -Value ""
+  }
+  Add-Content -Path $PROFILE -Value $vfoxLine
+}
 
 # 对于 Clink:
 # 1. 安装 clink: https://github.com/chrisant996/clink/releases
@@ -124,4 +132,3 @@ $ node -v
 
 [Apache 2.0 license](./LICENSE) - Copyright (C) 2026 Han Li
 and [contributors](https://github.com/version-fox/vfox/graphs/contributors)
-

docs/guides/quick-start.md

@@ -116,9 +116,19 @@ echo 'vfox activate fish | source' >> ~/.config/fish/config.fish
 Create PowerShell configuration:
 
 ```powershell
-if (-not (Test-Path -Path $PROFILE)) { New-Item -Type File -Path $PROFILE -Force }; Add-Content -Path $PROFILE -Value 'Invoke-Expression "$(vfox activate pwsh)"'
+if (-not (Test-Path -Path $PROFILE)) { New-Item -Type File -Path $PROFILE -Force | Out-Null }
+$vfoxLine = 'Invoke-Expression "$(vfox activate pwsh)"'
+$profileContent = Get-Content -Path $PROFILE -Raw
+if ($profileContent -notmatch [regex]::Escape($vfoxLine)) {
+  if ($profileContent.Length -gt 0 -and -not $profileContent.EndsWith("`r`n") -and -not $profileContent.EndsWith("`n")) {
+    Add-Content -Path $PROFILE -Value ""
+  }
+  Add-Content -Path $PROFILE -Value $vfoxLine
+}
 ```
 
+This snippet is safe to run multiple times. It avoids duplicating the vfox activation line and ensures it is written on a new line.
+
 If PowerShell prompts "cannot be loaded because the execution of scripts is disabled on this system", **run PowerShell as Administrator** and execute:
 
 ```powershell
@@ -344,4 +354,3 @@ Congratulations on completing the `vfox` quick start! Now you can:
 **Next Steps**:
 
 Use `vfox --help` to see more commands and options, or visit [All Commands](../usage/all-commands.md) to learn more features. 
-

docs/zh-hans/guides/quick-start.md

@@ -116,9 +116,19 @@ echo 'vfox activate fish | source' >> ~/.config/fish/config.fish
 创建 PowerShell 配置：
 
 ```powershell
-if (-not (Test-Path -Path $PROFILE)) { New-Item -Type File -Path $PROFILE -Force }; Add-Content -Path $PROFILE -Value 'Invoke-Expression "$(vfox activate pwsh)"'
+if (-not (Test-Path -Path $PROFILE)) { New-Item -Type File -Path $PROFILE -Force | Out-Null }
+$vfoxLine = 'Invoke-Expression "$(vfox activate pwsh)"'
+$profileContent = Get-Content -Path $PROFILE -Raw
+if ($profileContent -notmatch [regex]::Escape($vfoxLine)) {
+  if ($profileContent.Length -gt 0 -and -not $profileContent.EndsWith("`r`n") -and -not $profileContent.EndsWith("`n")) {
+    Add-Content -Path $PROFILE -Value ""
+  }
+  Add-Content -Path $PROFILE -Value $vfoxLine
+}
 ```
 
+这段脚本可以重复执行。它会避免重复写入 vfox 激活行，并确保该行写入到新的一行中。
+
 如果 PowerShell 提示「在此系统上禁止运行脚本」，请**以管理员身份运行 PowerShell** 并执行：
 
 ```powershell