diff --git a/home/.chezmoiscripts/windows/run_onchange_set-windows-terminal-powershell-args.ps1.tmpl b/home/.chezmoiscripts/windows/run_onchange_set-windows-terminal-powershell-args.ps1
similarity index 65%
rename from home/.chezmoiscripts/windows/run_onchange_set-windows-terminal-powershell-args.ps1.tmpl
rename to home/.chezmoiscripts/windows/run_onchange_set-windows-terminal-powershell-args.ps1
index d55bac56..9b890f52 100644
--- a/home/.chezmoiscripts/windows/run_onchange_set-windows-terminal-powershell-args.ps1.tmpl
+++ b/home/.chezmoiscripts/windows/run_onchange_set-windows-terminal-powershell-args.ps1
@@ -1,4 +1,4 @@
-# {{ if eq .chezmoi.os "windows" }}
+#!/usr/bin/env pwsh
 # Start the Windows Terminal PowerShell profile quietly.
 #
 # Two lines of noise appear before anything useful:
@@ -18,9 +18,25 @@
 # As with the sibling default-profile script, Windows Terminal owns
 # settings.json and every machine has a different, hand-tuned config, so only
 # this one profile's commandline is touched.
+#
+# Deliberately NOT a .tmpl: the signing workflow skips *.ps1.tmpl (a rendered
+# template no longer matches its signature), and this script needs no template
+# input. The OS guard the sibling templates carry is redundant here because
+# .chezmoiignore already drops .chezmoiscripts/windows/** on non-Windows, and
+# the module path comes from CHEZMOI_SOURCE_DIR, which chezmoi exports to every
+# script it runs.
 $ErrorActionPreference = "Stop"
 
-$modulePath = "{{ .chezmoi.sourceDir }}\dot_config\powershell\modules\DotfilesHelpers"
+# CHEZMOI_SOURCE_DIR arrives with forward slashes (and sometimes in 8.3 form),
+# so build the path with Join-Path rather than string concatenation. Falling
+# back to the applied tree keeps the script usable when run by hand.
+if ($env:CHEZMOI_SOURCE_DIR) {
+    $modulePath = Join-Path $env:CHEZMOI_SOURCE_DIR "dot_config/powershell/modules/DotfilesHelpers"
+}
+else {
+    $modulePath = Join-Path $HOME ".config/powershell/modules/DotfilesHelpers"
+}
+
 if (Test-Path $modulePath) {
     Import-Module $modulePath -Force -DisableNameChecking
 }
@@ -40,4 +56,3 @@ if (-not $results) {
 elseif (-not ($results | Where-Object { $_.Status -in @('Updated', 'AlreadySet') })) {
     Write-Host "[SKIP] PowerShell Core profile not found; leaving commandline unchanged" -ForegroundColor Yellow
 }
-# {{ end }}
diff --git a/home/dot_config/fastfetch/status.ps1 b/home/dot_config/fastfetch/status.ps1
index eda48224..3b3f9b80 100644
--- a/home/dot_config/fastfetch/status.ps1
+++ b/home/dot_config/fastfetch/status.ps1
@@ -226,10 +226,16 @@ function Write-StatusSection {
 
     # UTF-8 without BOM: `cmd /c type` copies the bytes straight through to
     # fastfetch, so a BOM would show up as stray characters in the banner.
+    # The temp name is unique so a concurrent writer cannot claim it.
     $encoding = New-Object System.Text.UTF8Encoding($false)
-    $tmp = "$file.tmp"
-    [System.IO.File]::WriteAllText($tmp, ($Value + "`r`n"), $encoding)
-    Move-Item -LiteralPath $tmp -Destination $file -Force
+    $tmp = '{0}.{1}.tmp' -f $file, [System.IO.Path]::GetRandomFileName()
+    try {
+        [System.IO.File]::WriteAllText($tmp, ($Value + "`r`n"), $encoding)
+        Move-Item -LiteralPath $tmp -Destination $file -Force
+    }
+    finally {
+        Remove-Item -LiteralPath $tmp -Force -ErrorAction SilentlyContinue
+    }
 }
 
 function Invoke-StatusRender {
diff --git a/home/dot_config/powershell/modules/DotfilesHelpers/Public/FastfetchStatus.ps1 b/home/dot_config/powershell/modules/DotfilesHelpers/Public/FastfetchStatus.ps1
index 9c3853e1..8d3ce294 100644
--- a/home/dot_config/powershell/modules/DotfilesHelpers/Public/FastfetchStatus.ps1
+++ b/home/dot_config/powershell/modules/DotfilesHelpers/Public/FastfetchStatus.ps1
@@ -208,8 +208,14 @@ function Update-FastfetchStatusCache {
     }
 
     # Drop rendered files whose source is gone (section no longer applies).
+    # Scoped deliberately narrowly: '.tmp' files belong to an in-flight write in
+    # this or another shell, and deleting one would break its Move-Item.
     foreach ($stale in @(Get-ChildItem -LiteralPath $CacheDir -File -ErrorAction SilentlyContinue |
-                Where-Object { $_.Name -notlike '*.src' -and $_.Name -notlike '.*' })) {
+                Where-Object {
+                    $_.Name -notlike '*.src' -and
+                    $_.Name -notlike '*.tmp' -and
+                    $_.Name -notlike '.*'
+                })) {
         if (-not (Test-Path -LiteralPath "$($stale.FullName).src")) {
             if ($PSCmdlet.ShouldProcess($stale.FullName, 'Remove orphaned fastfetch status section')) {
                 Remove-Item -LiteralPath $stale.FullName -Force -ErrorAction SilentlyContinue
@@ -344,9 +350,17 @@ function Write-FastfetchStatusFile {
 
     $encoding = New-Object System.Text.UTF8Encoding($false)
     $content = ($Lines -join "`r`n") + "`r`n"
-    $tmp = "$Path.tmp"
-    [System.IO.File]::WriteAllText($tmp, $content, $encoding)
-    Move-Item -LiteralPath $tmp -Destination $Path -Force
+    # Unique temp name: two shells starting at the same moment both render the
+    # same section, and a shared '<name>.tmp' would let one process's Move-Item
+    # pull the file out from under the other's.
+    $tmp = '{0}.{1}.tmp' -f $Path, [System.IO.Path]::GetRandomFileName()
+    try {
+        [System.IO.File]::WriteAllText($tmp, $content, $encoding)
+        Move-Item -LiteralPath $tmp -Destination $Path -Force
+    }
+    finally {
+        Remove-Item -LiteralPath $tmp -Force -ErrorAction SilentlyContinue
+    }
 }
 
 # SIG # Begin signature block
diff --git a/home/dot_config/powershell/profile.ps1 b/home/dot_config/powershell/profile.ps1
index 8d1fa66e..3220edfb 100644
--- a/home/dot_config/powershell/profile.ps1
+++ b/home/dot_config/powershell/profile.ps1
@@ -149,7 +149,10 @@ if ([Environment]::UserInteractive -and -not $env:CHEZMOI_SOURCE_DIR) {
                 if (-not $fastfetchProc.WaitForExit($fastfetchTimeoutMs)) {
                     try { $fastfetchProc.Kill() } catch { }
                     Write-Host "`n(fastfetch timed out after $([math]::Round($fastfetchTimeoutMs / 1000, 1))s; skipping)" -ForegroundColor DarkYellow
-                } else {
+                } elseif ($fastfetchProc.ExitCode -eq 0) {
+                    # Only a clean run actually painted a banner. A non-zero exit
+                    # (bad config, for instance) leaves the screen empty, so the
+                    # welcome lines below stay as the one sign of life.
                     $script:_fastfetchShown = $true
                 }
             } catch {
diff --git a/tests/powershell/FastfetchStatus.Tests.ps1 b/tests/powershell/FastfetchStatus.Tests.ps1
index 90a041ee..c32412a6 100644
--- a/tests/powershell/FastfetchStatus.Tests.ps1
+++ b/tests/powershell/FastfetchStatus.Tests.ps1
@@ -477,6 +477,29 @@ Describe "fastfetch status module helpers" {
             Join-Path $script:TestCacheDir 'updates' | Should -Not -Exist
         }
 
+        It "should not delete an in-flight temp file from a concurrent writer" {
+            # Cleanup used to remove any non-.src file, which could yank a
+            # '<name>.<random>.tmp' out from under another shell's Move-Item.
+            $inFlight = Join-Path $script:TestCacheDir 'updates.abc12345.tmp'
+            Set-Content -LiteralPath $inFlight -Value 'half-written'
+            Set-Content -LiteralPath (Join-Path $script:TestCacheDir 'updates.src') -Value 'line'
+
+            Update-FastfetchStatusCache -SkipRefresh
+
+            $inFlight | Should -Exist
+        }
+
+        It "should give each write a unique temp name" {
+            # Two shells starting together both render the same section; a
+            # shared '<name>.tmp' would make one of the writes fail.
+            $target = Join-Path $script:TestCacheDir 'concurrent'
+            Write-FastfetchStatusFile -Path $target -Lines 'one'
+            Write-FastfetchStatusFile -Path $target -Lines 'two'
+
+            (Get-Content -LiteralPath $target -Raw).Trim() | Should -Be 'two'
+            @(Get-ChildItem -LiteralPath $script:TestCacheDir -Filter '*.tmp') | Should -BeNullOrEmpty
+        }
+
         It "should leave the stamp alone" {
             Set-Content -LiteralPath (Join-Path $script:TestCacheDir 'updates.src') -Value 'line'
             Update-FastfetchStatusCache -SkipRefresh
diff --git a/tests/powershell/Profile.Tests.ps1 b/tests/powershell/Profile.Tests.ps1
index a40385c8..b212f36c 100644
--- a/tests/powershell/Profile.Tests.ps1
+++ b/tests/powershell/Profile.Tests.ps1
@@ -486,6 +486,12 @@ Describe "Profile startup noise" {
         $script:ProfileContent | Should -Match 'if \(-not \$fastfetchProc\.WaitForExit'
     }
 
+    It "Profile should not mark fastfetch as shown when it exited non-zero" {
+        # Exiting quickly is not the same as succeeding: a bad config leaves the
+        # screen blank, and suppressing the welcome lines would look like a hang.
+        $script:ProfileContent | Should -Match '\$fastfetchProc\.ExitCode -eq 0'
+    }
+
     It "Profile should keep the welcome lines for installs without fastfetch" {
         $script:ProfileContent | Should -Match 'PowerShell Profile Loaded'
         $script:ProfileContent | Should -Match "Type 'aliases' to see available aliases"
diff --git a/tests/powershell/WindowsTerminal.Tests.ps1 b/tests/powershell/WindowsTerminal.Tests.ps1
index e4a97f3a..3afd66e1 100644
--- a/tests/powershell/WindowsTerminal.Tests.ps1
+++ b/tests/powershell/WindowsTerminal.Tests.ps1
@@ -484,6 +484,46 @@ Describe "Set-WindowsTerminalProfileCommandLine Function" -Tag "Unit" {
     }
 }
 
+Describe "Windows Terminal PowerShell args script" -Tag "Unit" {
+    BeforeAll {
+        $script:ArgsScript = Join-Path $script:RepoRoot `
+            "home\.chezmoiscripts\windows\run_onchange_set-windows-terminal-powershell-args.ps1"
+    }
+
+    It "Should exist as a plain .ps1 so the signing workflow can sign it" {
+        # sign-powershell.yml signs **.ps1 but excludes **.ps1.tmpl, because a
+        # rendered template no longer matches its signature.
+        $script:ArgsScript | Should -Exist
+        "$script:ArgsScript.tmpl" | Should -Not -Exist
+    }
+
+    It "Should have valid PowerShell syntax" {
+        $errors = $null
+        [System.Management.Automation.Language.Parser]::ParseFile(
+            $script:ArgsScript, [ref]$null, [ref]$errors) | Out-Null
+        $errors | Should -BeNullOrEmpty
+    }
+
+    It "Should not contain chezmoi template syntax" {
+        $content = Get-Content $script:ArgsScript -Raw
+        $content | Should -Not -Match '\{\{'
+    }
+
+    It "Should resolve the module through CHEZMOI_SOURCE_DIR" {
+        $content = Get-Content $script:ArgsScript -Raw
+        $content | Should -Match 'CHEZMOI_SOURCE_DIR'
+        # Forward slashes and 8.3 paths arrive in that variable, so the path has
+        # to be composed rather than concatenated.
+        $content | Should -Match 'Join-Path'
+    }
+
+    It "Should quieten both pwsh startup lines" {
+        $content = Get-Content $script:ArgsScript -Raw
+        $content | Should -Match '-NoLogo'
+        $content | Should -Match '-NoProfileLoadTime'
+    }
+}
+
 Describe "Set-WindowsTerminalCopilotProfile Function" -Tag "Unit" {
     BeforeEach {
         $script:settingsPath = Join-Path $script:TestDir.FullName "settings-$(Get-Random).json"