Add Windows ARM64 build target to release workflow

[rianjs]

Summary

Add Windows ARM64 (windows_arm64) build target to the release workflow. Currently we build ARM64 for macOS and Linux, but not Windows.

Current State

Release artifacts include:

• darwin_amd64, darwin_arm64 ✅
• linux_amd64, linux_arm64 ✅
• windows_amd64 ✅
• windows_arm64 ❌ missing

Implementation

Add GOOS=windows GOARCH=arm64 to the build matrix in the release workflow. This is a one-liner since Go cross-compilation handles the rest.

Acceptance Criteria

• Windows ARM64 binary is built during release
• cfl_X.Y.Z_windows_arm64.zip artifact appears in GitHub Releases
• Checksum for ARM64 artifact included in checksums.txt

Why

Prerequisite for Windows package distribution (Chocolatey, Winget) with ARM64 support.

[rianjs]

Implementation Plan

Analysis

The release workflow uses GoReleaser (.goreleaser.yml). The build configuration already includes all OS/arch combinations:

• goos: [darwin, linux, windows]
• goarch: [amd64, arm64]

However, there's an explicit ignore block at lines 23-25 that excludes windows/arm64:

ignore:
  - goos: windows
    goarch: arm64

Change Required

Remove the ignore block from .goreleaser.yml. This is a 3-line deletion.

What Happens Automatically

Once the ignore block is removed, GoReleaser will:

1. Build cfl.exe for windows/arm64
2. Package it as cfl_X.Y.Z_windows_arm64.zip (per the format_overrides config)
3. Include its checksum in checksums.txt (per the checksum config)

Verification

• Run goreleaser build --snapshot --clean locally to verify the windows_arm64 binary is produced
• Check the dist/ directory for cfl_windows_arm64_v1/cfl.exe

Files Changed

• .goreleaser.yml - remove lines 23-25 (the ignore block)