ci: add release pipeline with GitHub Actions and one-line installer

[Mercurial]

Context

We've implemented an automated release pipeline in Helix that works really well. We should adopt the same pattern for Argus.

Reference implementation: https://github.com/SAIB-Inc/Helix/blob/main/.github/workflows/release.yml

What Helix does

1. Release workflow (.github/workflows/release.yml):

   • Triggered on pushing v*.*.* tags
   • Builds self-contained, single-file, trimmed .NET binaries for multiple platforms (linux-x64, linux-arm64, osx-x64, osx-arm64)
   • Packages each as a .tar.gz
   • Creates a GitHub Release with all assets attached via softprops/action-gh-release@v2
   • Auto-generates changelog from conventional commit messages between tags

2. One-line installer (install.sh):

   • curl -fsSL https://raw.githubusercontent.com/SAIB-Inc/Helix/main/install.sh | bash
   • Detects platform (OS + arch) and downloads the correct binary
   • Installs to ~/.helix/bin/ (no sudo required)
   • Configures PATH for zsh, bash, and fish shells
   • Supports HELIX_VERSION env var to pin a specific version

3. Publish configuration (.csproj):

   • AssemblyName set to the CLI name
   • Self-contained + trimmed + compressed single-file publish (conditional on PublishSingleFile=true so dev builds are unaffected)
   • TrimmerRootAssembly for reflection-discovered assemblies
   • --version flag support

Tasks

• Adapt the release workflow for Argus (adjust RIDs, project path, binary name)
• Create install.sh for Argus
• Add publish configuration to the appropriate .csproj
• Add --version flag
• Test the full flow: tag → build → release → install