This PR adds a comprehensive .github/copilot-instructions.md file that provides GitHub Copilot coding agents with detailed instructions for working effectively in the gitopssets-controller codebase.

What's Included

The instructions cover all essential development workflows with validated commands and timing:

Build & Test Process:

• Complete bootstrap sequence: make manifests generate fmt vet (3-4 minutes)
• Binary builds: make build (~10 seconds) and CLI tool compilation
• Test suites: make test (30-45 seconds) and make e2e-tests (10-20 seconds)
• Documentation generation: make api-docs (~35 seconds)

Validation Scenarios:

• CLI functionality testing with working examples (list, matrix, repeated-list generators)
• Manual validation workflows for ensuring changes work correctly
• Pre-commit validation steps to prevent CI failures

Development Guidance:

• Repository structure reference with key directories and file locations
• Example categorization (which work offline vs require cluster access)
• Docker build and Kubernetes deployment workflows
• Troubleshooting common issues and performance considerations

Key Features

• Exhaustively validated: Every command was tested and timed during development
• Timeout recommendations: Includes "NEVER CANCEL" warnings with specific time estimates
• Manual testing scenarios: Provides concrete examples agents can run to verify functionality
• Security considerations: Guidelines for safe development practices

The instructions start with a clear directive to follow them first before falling back to additional search, ensuring agents work efficiently with known-good patterns.

Fixes #319.

💬 Share your feedback on Copilot coding agent for the chance to win a $200 gift card! Click here to start the survey.