fix(build): Use -arch x64 flag for WiX build instead of Package attribute

The Platform attribute is not valid in WiX v4+. Instead, specify the
target architecture at build time using the -arch x64 flag.

Changes:
- Remove invalid Platform="x64" attribute from Package element
- Add -arch x64 to wix build command in release workflow
- Keep ProgramFiles64Folder for explicit 64-bit installation path

This ensures the MSI is built as a proper 64-bit package that installs
to "Program Files" instead of "Program Files (x86)".

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.github/workflows/release.yml

@@ -109,7 +109,7 @@ jobs:
       run: Compress-Archive -Path ./installer/* -DestinationPath ./CCExtractor.${{ steps.get_version.outputs.DISPLAY_VERSION }}_win_portable.zip
       working-directory: ./windows
     - name: Build installer
-      run:  wix build -ext WixToolset.UI.wixext -d "AppVersion=${{ steps.get_version.outputs.VERSION }}" -o CCExtractor.${{ steps.get_version.outputs.DISPLAY_VERSION }}.msi installer.wxs CustomUI.wxs
+      run:  wix build -arch x64 -ext WixToolset.UI.wixext -d "AppVersion=${{ steps.get_version.outputs.VERSION }}" -o CCExtractor.${{ steps.get_version.outputs.DISPLAY_VERSION }}.msi installer.wxs CustomUI.wxs
       working-directory: ./windows
     - name: Upload as asset
       uses: AButler/upload-release-assets@v3.0