fix(init): preserve existing README.md / CHANGELOG.md on re-run

The README and CHANGELOG generation steps used Move-Item -Force, which
silently overwrites the destination. The top-of-script "already
initialized" check is just a warning the user can dismiss, so a re-run
after customization (e.g., user re-runs init to redo something, or
template files reappear via git checkout) could clobber their work.

Guard each move on the destination not existing. If both source and
destination are present, warn and leave both in place — manual
resolution is safer than picking a side automatically.

Addresses CodeRabbit feedback on PR #16.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: tablackburn

Initialize-Template.ps1

@@ -281,21 +281,34 @@ if (Test-Path -Path $docsFolder) {
 }
 
 # Replace template-facing README.md with the module-facing README.template.md
-# (placeholders inside README.template.md were already substituted by the file-processing loop above)
+# (placeholders inside README.template.md were already substituted by the file-processing loop above).
+# If the destination already exists (e.g., the user is re-running init after customizing it),
+# leave both files in place and warn — manually resolving is safer than overwriting customizations.
 $readmeTemplate = Join-Path -Path $PSScriptRoot -ChildPath 'README.template.md'
 $readmePath = Join-Path -Path $PSScriptRoot -ChildPath 'README.md'
 if (Test-Path -Path $readmeTemplate) {
-    Move-Item -Path $readmeTemplate -Destination $readmePath -Force
-    Write-Host '  Generated module README.md from template' -ForegroundColor Green
+    if (Test-Path -Path $readmePath) {
+        Write-Warning '  README.md already exists; leaving it in place. Resolve README.template.md manually.'
+    }
+    else {
+        Move-Item -Path $readmeTemplate -Destination $readmePath
+        Write-Host '  Generated module README.md from template' -ForegroundColor Green
+    }
 }
 
 # Replace template-facing CHANGELOG.md with the module-facing CHANGELOG.template.md
-# (placeholders inside CHANGELOG.template.md were already substituted by the file-processing loop above)
+# (placeholders inside CHANGELOG.template.md were already substituted by the file-processing loop above).
+# Same guard as README above — preserve any existing CHANGELOG.md rather than clobber it.
 $changelogTemplate = Join-Path -Path $PSScriptRoot -ChildPath 'CHANGELOG.template.md'
 $changelogPath = Join-Path -Path $PSScriptRoot -ChildPath 'CHANGELOG.md'
 if (Test-Path -Path $changelogTemplate) {
-    Move-Item -Path $changelogTemplate -Destination $changelogPath -Force
-    Write-Host '  Generated module CHANGELOG.md from template' -ForegroundColor Green
+    if (Test-Path -Path $changelogPath) {
+        Write-Warning '  CHANGELOG.md already exists; leaving it in place. Resolve CHANGELOG.template.md manually.'
+    }
+    else {
+        Move-Item -Path $changelogTemplate -Destination $changelogPath
+        Write-Host '  Generated module CHANGELOG.md from template' -ForegroundColor Green
+    }
 }
 
 # Initialize Git repository if requested