Windows on ARM64: release builds, PE header check, install test on ARM64 hardware

Release builds add an arm64 MSI and portable zip, cross-compiled on the x64
runner (signing and WiX as for x64). package.ps1 checks each binary's PE
header before packaging: Machine must match -Arch, the app must be a GUI
program and the CLI a console program. It skips the CLI smoke run when an
ARM64 build can't run on the host. A new Windows ARM64 workflow packages the
ARM64 MSI, installs it on a Windows 11 ARM64 runner, checks both installed
exes are ARM64, runs the CLI, and uninstalls. Ported from printcraft#66.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

.github/workflows/release.yml

@@ -112,6 +112,9 @@ jobs:
         include:
           - { arch: x64, target: x86_64-pc-windows-msvc }
           - { arch: x86, target: i686-pc-windows-msvc }
+          # Windows on ARM: cross-compiled on the x64 runner, so signing and WiX run as above.
+          # .github/workflows/windows-arm64.yml installs and runs it on ARM64 hardware.
+          - { arch: arm64, target: aarch64-pc-windows-msvc }
     env:
       EFFECTCRAFT_VERSION: ${{ needs.version.outputs.version }}
       EFFECTCRAFT_BUILD_DATE: ${{ needs.version.outputs.date }}