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

What's Included

The instructions provide exhaustive guidance on:

Build & Test Procedures:

• Exact commands for building development and release versions with validated timings
• Testing procedures including format checking and CI requirements
• Proper timeout specifications with "NEVER CANCEL" warnings for long-running operations

Developer Workflow:

• Step-by-step validation scenarios for testing changes
• Complete key generation and CLI functionality testing procedures
• Error handling validation and expected outputs

Project Structure:

• Detailed overview of the Rust-based architecture using Cargo
• Key dependencies and their purposes (HPKE encryption, clap CLI, etc.)
• File organization and module responsibilities

Platform Considerations:

• Cross-platform compatibility notes for Linux, macOS, and Windows
• scriptreplay dependency requirements for PTY session replay
• GitHub Actions CI/CD pipeline integration

Validation

All commands and procedures in the instructions have been validated by:

1. Executing every build and test command to measure actual timings
2. Testing the complete key generation workflow
3. Verifying CLI help system and error handling
4. Confirming format checking and CI requirements work correctly

The instructions follow the specified guidelines with imperative tone, exhaustive validation, and focus on commands that actually work. Build times are documented as:

• Fresh builds: 31-52 seconds (timeout: 300+ seconds)
• Release builds: ~41 seconds (timeout: 300+ seconds)
• Incremental builds: 1-2 seconds
• Tests: 5-10 seconds

This also includes a minor fix to the pty.rs module to ensure the project builds successfully, implementing a minimal generate_replay function that was referenced but missing.

Fixes #4.

💡 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.