Fix Windows CI compatibility and binary build issues

[Copilot]

Fixes Windows compatibility issues in the CI pipeline as referenced in PR #213, enabling cross-platform testing on Windows and macOS in addition to Linux.

Issues Fixed

1. GitHub Actions Syntax Issues

The original PR had incorrect conditional syntax that would cause workflow failures. Fixed if conditions to use proper GitHub Actions syntax:

- if: runner.os == 'Linux'
+ if: ${{ runner.os == 'Linux' }}

2. Windows Binary Build Problem

The build-npm.mjs script was not generating Windows executables with the required .exe extension, causing runtime failures on Windows:

- await $`GOOS=${platform.os} GOARCH=${platform.arch} go build -o npm/${platform['node-os'] || platform.os}-${platform['node-arch']}/rslint ./cmd/rslint`;
+ const binaryName = platform.os === 'windows' ? 'rslint.exe' : 'rslint';
+ await $`GOOS=${platform.os} GOARCH=${platform.arch} go build -o npm/${platform['node-os'] || platform.os}-${platform['node-arch']}/${binaryName} ./cmd/rslint`;

3. Platform-Specific Caching Conflicts

Updated cache keys to be OS-specific to prevent cache conflicts between different platforms:

- key: 'vscode-test'
+ key: vscode-test-${{ matrix.os }}

Changes Made

• Multi-platform CI: Added matrix strategy to run tests on Ubuntu, Windows, and macOS
• Conditional Dependencies: Linux-specific packages (xvfb) now only install on Linux
• Binary Compatibility: Windows builds now correctly generate .exe executables
• Cache Isolation: Each platform gets its own cache namespace
• Runner Optimization: Final status job uses standard ubuntu-latest runner

Testing

• ✅ YAML syntax validated
• ✅ GitHub Actions conditional logic verified
• ✅ Build process tested and functional
• ✅ TypeScript compilation passes
• ✅ Linting passes with only pre-existing warnings

The CI will now properly test RSLint across all three major platforms, ensuring Windows users have a fully functional linting experience.

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