chore: promote staging to production

[wagnert]

Promote staging to production

This PR promotes all tested features from staging to main for production deployment.

Major Changes

Git-Flow & CI/CD

• ✅ Implement Git-Flow with develop → staging → main branches
• ✅ Add GitHub Actions workflows for CI, staging, and production deployments
• ✅ Configure branch protection rules and environment-based deployments
• ✅ Add automated release workflow with changelog generation

Testing Infrastructure

• ✅ Separate tests from source code (tests/ directory)
• ✅ Add AppSheetClientInterface for polymorphic client usage
• ✅ Create MockAppSheetClient with in-memory storage for testing
• ✅ Add comprehensive test suite (48 tests) with JSDoc documentation
• ✅ Fix Jest/ES module compatibility with uuid mock

Documentation

• ✅ Add CONTRIBUTING.md with Git-Flow and Semantic Versioning guidelines
• ✅ Add CHANGELOG.md with version history template
• ✅ Create .github/GIT-FLOW.md quick reference
• ✅ Create .github/BRANCH-PROTECTION.md configuration guide
• ✅ Add comprehensive JSDoc comments to all test files
• ✅ Update README.md with Git-Flow and versioning sections
• ✅ Update CLAUDE.md with Git-Flow strategy

Semantic Versioning

• ✅ Add npm scripts for version management (patch/minor/major/prerelease)
• ✅ Configure automated release process
• ✅ Add Conventional Commits guidelines

Test Results

Test Suites: 2 passed, 2 total
Tests:       48 passed, 48 total
Build:       ✅ Success
Linting:     ✅ Passed

Deployment

This will auto-deploy to Production environment upon merge.

Files Changed

27 files changed, 4330 insertions(+), 378 deletions(-)

🤖 Generated with Claude Code

Co-Authored-By: Claude noreply@anthropic.com