Fix timestamp file creation for TeamCity Docker builds

Create timestamp file for all Docker image builds, not just -Claude mode.
The file only affects Dockerfiles that COPY it (Dockerfile.claude).

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: gfraiteur

CLAUDE.md

@@ -127,3 +127,8 @@ Invoke-RestMethod -Uri "https://postsharp.teamcity.com/app/rest/buildQueue" -Met
 4. Bump version (see above)
 5. Monitor version bumping
 6. When completed, schedule deploy public
+
+
+## Warnings
+
+NEVER COMMIT WITHOUT USER APPROVAL. Even if the user has given approval for a prior commit.

DockerBuild.ps1

@@ -458,23 +458,24 @@ Write-Host "Preparing context and mounts." -ForegroundColor Green
 # Create secrets JSON file.
 if (-not $KeepEnv)
 {
+        # Create timestamp file for cache invalidation (only if building image)
+    # This is used by Dockerfile.claude but doesn't affect other Dockerfiles
+    if (-not $NoBuildImage)
+    {
+        if ($env:IS_TEAMCITY_AGENT)
+        {
+            $timestampFile = New-TeamCityTimestampFile -TimestampValue $Timestamp -DockerContextDir $dockerContextDirectory
+        }
+        else
+        {
+            $timestampFile = Get-TimestampFile -Update:$Update
+        }
+    }
+
     if ($Claude)
     {
         # Use Claude-specific environment variables (filtered and renamed)
         New-ClaudeEnvJson
-
-        # Get/update timestamp file for cache invalidation (only if building image)
-        if (-not $NoBuildImage)
-        {
-            if ($env:IS_TEAMCITY_AGENT)
-            {
-                $timestampFile = New-TeamCityTimestampFile -TimestampValue $Timestamp -DockerContextDir $dockerContextDirectory
-            }
-            else
-            {
-                $timestampFile = Get-TimestampFile -Update:$Update
-            }
-        }
     }
     else
     {
@@ -1039,9 +1040,9 @@ foreach (`$dir in `$gitDirectories) {
     $initScriptContent | Set-Content -Path $initScript -Encoding UTF8
 }
 
-# Copy timestamp file to docker context (for Claude mode cache invalidation)
+# Copy timestamp file to docker context (for cache invalidation)
 # Skip if running on TeamCity - we already created the file directly in docker-context
-if ($Claude -and $timestampFile -and -not $env:IS_TEAMCITY_AGENT)
+if ($timestampFile -and -not $env:IS_TEAMCITY_AGENT)
 {
     $gDirectory = Join-Path $dockerContextDirectory ".g"
     if (-not (Test-Path $gDirectory))

src/PostSharp.Engineering.BuildTools/Resources/DockerBuild.ps1

@@ -458,23 +458,24 @@ Write-Host "Preparing context and mounts." -ForegroundColor Green
 # Create secrets JSON file.
 if (-not $KeepEnv)
 {
+        # Create timestamp file for cache invalidation (only if building image)
+    # This is used by Dockerfile.claude but doesn't affect other Dockerfiles
+    if (-not $NoBuildImage)
+    {
+        if ($env:IS_TEAMCITY_AGENT)
+        {
+            $timestampFile = New-TeamCityTimestampFile -TimestampValue $Timestamp -DockerContextDir $dockerContextDirectory
+        }
+        else
+        {
+            $timestampFile = Get-TimestampFile -Update:$Update
+        }
+    }
+
     if ($Claude)
     {
         # Use Claude-specific environment variables (filtered and renamed)
         New-ClaudeEnvJson
-
-        # Get/update timestamp file for cache invalidation (only if building image)
-        if (-not $NoBuildImage)
-        {
-            if ($env:IS_TEAMCITY_AGENT)
-            {
-                $timestampFile = New-TeamCityTimestampFile -TimestampValue $Timestamp -DockerContextDir $dockerContextDirectory
-            }
-            else
-            {
-                $timestampFile = Get-TimestampFile -Update:$Update
-            }
-        }
     }
     else
     {
@@ -1039,9 +1040,9 @@ foreach (`$dir in `$gitDirectories) {
     $initScriptContent | Set-Content -Path $initScript -Encoding UTF8
 }
 
-# Copy timestamp file to docker context (for Claude mode cache invalidation)
+# Copy timestamp file to docker context (for cache invalidation)
 # Skip if running on TeamCity - we already created the file directly in docker-context
-if ($Claude -and $timestampFile -and -not $env:IS_TEAMCITY_AGENT)
+if ($timestampFile -and -not $env:IS_TEAMCITY_AGENT)
 {
     $gDirectory = Join-Path $dockerContextDirectory ".g"
     if (-not (Test-Path $gDirectory))