Add itch.io integration for automatic game publishing

[Copilot]

This PR adds comprehensive itch.io integration that automatically publishes the game to itch.io when new releases are created, addressing the need for automatic game distribution.

What's Added

GitHub Actions Workflow

• .github/workflows/itch-io-deploy.yml - Automated deployment workflow that:
  • Triggers on GitHub releases (automatic)
  • Supports manual deployment via workflow dispatch
  • Uses itch.io's official butler CLI tool for reliable uploads
  • Builds the game, packages it, and uploads to the html channel
  • Provides detailed deployment summaries and error handling

Documentation

• docs/ITCH_IO_SETUP.md - Comprehensive setup guide with:

  • Step-by-step itch.io account and game page setup
  • GitHub secrets configuration instructions
  • Troubleshooting guide for common issues
  • Security notes and advanced configuration options

• docs/DEPLOYMENT.md - Complete deployment overview covering all platforms:

  • GitHub Pages, Render.com, itch.io, Docker, and PR previews
  • Deployment flow diagram and comparison matrix
  • Version management and manual deployment instructions

UI Updates

• Added itch.io badges and play button to README.md
• Updated deployment section with itch.io integration details
• Added workflow status badge for itch.io deployments

How It Works

1. Automatic: When a GitHub release is published, the workflow automatically builds and deploys to itch.io
2. Manual: Developers can trigger deployment for any tag via GitHub Actions
3. Versioned: Game versions on itch.io match GitHub release tags
4. Secure: Uses repository secrets for API key management

Setup Requirements

Three repository secrets enable the integration:

• BUTLER_API_KEY (required) - itch.io API key for authentication
• ITCH_USER (optional) - itch.io username, defaults to "commjoen"
• ITCH_GAME (optional) - game slug, defaults to "generated-game-experiment"

Validation

• ✅ Build process tested and verified
• ✅ Workflow YAML syntax validated
• ✅ Package structure confirmed compatible with itch.io
• ✅ All existing tests continue to pass
• ✅ Integration follows existing CI/CD patterns

The game will be available at: https://commjoen.itch.io/generated-game-experiment

Fixes #72.

Warning

Firewall rules blocked me from connecting to one or more addresses

I tried to connect to the following addresses, but was blocked by firewall rules:

• broth.itch.ovh
  • Triggering command: curl -L -o butler.zip REDACTED (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

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💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.

[github-actions]

🚀 Preview deployed!

Your changes are now available at: https://commjoen.github.io/generated-game-experiment/pr-73/

This preview will be automatically cleaned up when the PR is closed or merged.

[github-actions]

🚀 Preview deployed!

Your changes are now available at: https://commjoen.github.io/generated-game-experiment/pr-73/

This preview will be automatically cleaned up when the PR is closed or merged.

[github-actions]

🚀 Preview deployed!

Your changes are now available at: https://commjoen.github.io/generated-game-experiment/pr-73/

This preview will be automatically cleaned up when the PR is closed or merged.

[github-actions]

🚀 Preview deployed!

Your changes are now available at: https://commjoen.github.io/generated-game-experiment/pr-73/

This preview will be automatically cleaned up when the PR is closed or merged.