fix: make packaged updater handshake Windows-safe

scripts/apply-binary-update.ps1

@@ -7,7 +7,8 @@ param(
   [Parameter(Mandatory = $true)][int]$ParentPid,
   [Parameter(Mandatory = $true)][string]$LogPath,
   [Parameter(Mandatory = $true)][string]$StatusPath,
-  [Parameter(Mandatory = $true)][string]$UpdateId
+  [Parameter(Mandatory = $true)][string]$UpdateId,
+  [switch]$HandshakeOnly
 )
 
 $ErrorActionPreference = "Stop"
@@ -27,12 +28,26 @@ function Write-UpdateState {
     updatedAt = [DateTime]::UtcNow.ToString("o")
   }
   if ($State -in @("success", "failed", "rolled-back")) { $payload.completedAt = [DateTime]::UtcNow.ToString("o") }
+  $directory = Split-Path -Parent $StatusPath
+  if ($directory) { New-Item -ItemType Directory -Force -Path $directory | Out-Null }
   $temporary = "$StatusPath.$PID.tmp"
-  $payload | ConvertTo-Json -Depth 4 | Set-Content -LiteralPath $temporary -Encoding UTF8
-  if (Test-Path -LiteralPath $StatusPath) { [IO.File]::Replace($temporary, $StatusPath, $null) }
-  else { Move-Item -LiteralPath $temporary -Destination $StatusPath }
+  $backup = "$StatusPath.$PID.bak"
+  $json = $payload | ConvertTo-Json -Depth 4
+  $utf8NoBom = New-Object System.Text.UTF8Encoding($false)
+  [IO.File]::WriteAllText($temporary, $json, $utf8NoBom)
+  try {
+    if ([IO.File]::Exists($StatusPath)) {
+      [IO.File]::Replace($temporary, $StatusPath, $backup)
+      [IO.File]::Delete($backup)
+    } else {
+      [IO.File]::Move($temporary, $StatusPath)
+    }
+  } catch {
+    [IO.File]::Copy($temporary, $StatusPath, $true)
+    [IO.File]::Delete($temporary)
+    if ([IO.File]::Exists($backup)) { [IO.File]::Delete($backup) }
+  }
 }
-
 function Write-Log([string]$Message) {
   "{0} {1}" -f [DateTime]::UtcNow.ToString("o"), $Message | Add-Content -LiteralPath $LogPath -Encoding UTF8
 }
@@ -40,6 +55,10 @@ function Write-Log([string]$Message) {
 try {
   Write-UpdateState -State "started" -Message "Binary updater owns the update request."
   Write-Log "Validating ForgeFlow $ExpectedVersion binary update."
+  if ($HandshakeOnly) {
+    Write-Log "Handshake-only verification completed successfully."
+    exit 0
+  }
   $actualSha256 = (Get-FileHash -LiteralPath $BinaryPath -Algorithm SHA256).Hash.ToLowerInvariant()
   if ($actualSha256 -ne $ExpectedSha256.ToLowerInvariant()) { throw "Binary update SHA-256 verification failed." }
   if (-not (Test-Path -LiteralPath $CurrentExecutable -PathType Leaf)) { throw "Current ForgeFlow executable was not found." }

scripts/apply-source-update.ps1

@@ -54,15 +54,20 @@ function Write-UpdateState {
     if ([System.IO.File]::Exists($StatusPath)) {
       # Windows PowerShell 5.1 does not reliably let Move-Item -Force replace
       # an existing file. File.Replace is atomic on the local NTFS volume.
-      [System.IO.File]::Replace($temporary, $StatusPath, $null)
+      $backup = "$StatusPath.$PID.bak"
+      [System.IO.File]::Replace($temporary, $StatusPath, $backup)
     } else {
       [System.IO.File]::Move($temporary, $StatusPath)
     }
   } catch {
     # Some filesystems do not implement File.Replace. Copy with overwrite is
     # the deterministic fallback; the temporary file is removed afterwards.
-    [System.IO.File]::Copy($temporary, $StatusPath, $true)
-    [System.IO.File]::Delete($temporary)
+    if ([System.IO.File]::Exists($temporary)) {
+      [System.IO.File]::Copy($temporary, $StatusPath, $true)
+      [System.IO.File]::Delete($temporary)
+    }
+  } finally {
+    if ([System.IO.File]::Exists($backup)) { [System.IO.File]::Delete($backup) }
   }
 }
 

scripts/verify.mjs

@@ -83,6 +83,7 @@ const required = [
   "docs/RELEASE_NOTES_0.10.1.md",
   "docs/RELEASE_NOTES_0.10.2.md",
   "docs/RELEASE_NOTES_0.10.3.md",
+  "docs/RELEASE_NOTES_0.10.4.md",
   "docs/UPDATING.md",
   "docs/DIAGNOSTICS.md",
   "docs/DEPLOYMENT_SETUP.md",
@@ -121,9 +122,9 @@ for (const file of required) await access(path.join(root, file));
 const packageJson = JSON.parse(
   await readFile(path.join(root, "package.json"), "utf8"),
 );
-if (packageJson.version !== "0.10.3")
+if (packageJson.version !== "0.10.4")
   throw new Error(
-    `Expected package version 0.10.3, got ${packageJson.version}.`,
+    `Expected package version 0.10.4, got ${packageJson.version}.`,
   );
 const sourceManifest = await readFile(
   path.join(root, "SOURCE_MANIFEST.txt"),
@@ -449,6 +450,10 @@ const release0103 = await readFile(path.join(root, "docs/RELEASE_NOTES_0.10.3.md
 for (const phrase of ["concurrently", "debounce", "animation frame", "Git Validator", "stale or forged"]) {
   if (!release0103.includes(phrase)) throw new Error(`0.10.3 release notes are missing: ${phrase}`);
 }
+const release0104 = await readFile(path.join(root, "docs/RELEASE_NOTES_0.10.4.md"), "utf8");
+for (const phrase of ["Windows PowerShell 5.1", "atomic status", "handshake-only", "existing installations"]) {
+  if (!release0104.includes(phrase)) throw new Error(`0.10.4 release notes are missing: ${phrase}`);
+}
 const configSource = await readFile(path.join(root, "src/main/config-store.cjs"), "utf8");
 for (const mode of ["server-git", "push-bundle", "monitor-only"]) {
   if (!configSource.includes(mode)) throw new Error(`Deployment configuration is missing mode: ${mode}`);