Migrate container publishing from Docker Hub to GHCR with automatic versioning

[Copilot]

Description

Migrates container image publishing from Docker Hub to GitHub Container Registry (GHCR) and implements automatic versioning on merge to main.

Key Changes:

• Release workflow (release.yml): Replaced Docker Hub authentication with GHCR using built-in GITHUB_TOKEN. Updated all image tags to ghcr.io/matthadfield113/smart-energy-controller. No repository secrets required.

• Auto-version workflow (auto-version.yml): New workflow that auto-increments patch version in config.json on push to main, commits the change, creates a git tag, and triggers the release workflow. Skippable via [skip-version] commit message. Ignores markdown, workflow, and test-only changes.

• Documentation: Updated CI/CD docs to reflect GHCR usage and automatic versioning behavior.

Workflow:

Push to main → Auto-increment version (1.2.0 → 1.2.1) → Commit + Tag → Release → GHCR

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring
• Performance improvement
• Test addition/update

Related Issue

Fixes #20

Testing

Test Configuration

• Workflows: GitHub Actions
• Python Version: 3.11
• YAML validation: Passed

Test Steps

1. Validated YAML syntax for both workflow files
2. Tested version increment logic (1.2.0 → 1.2.1)
3. Verified no Docker Hub references remain in workflows
4. Confirmed GHCR authentication uses GITHUB_TOKEN
5. Validated workflow permissions (contents: write, packages: write)
6. Ran CodeQL security scan (0 alerts)

Checklist

• My code follows the code style of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published
• I have updated the CHANGELOG.md

Screenshots (if applicable)

N/A - Workflow configuration changes only

Additional Notes

• No DOCKER_USERNAME or DOCKER_PASSWORD secrets needed - uses built-in GITHUB_TOKEN
• Auto-versioning only triggers on code changes (ignores docs/workflows/tests)
• To skip versioning: include [skip-version] in commit message
• Images will be available at: ghcr.io/matthadfield113/smart-energy-controller:v{version}-{arch}

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Push to GHCR instead of Docker Hub</issue_title>
<issue_description>Push the containers to GHCR instead of docker hub.

We should also change the version every time some new code is merged to main and make a new release.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Push to GHCR instead of Docker Hub #20

---

💡 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.