✨ Set up Copilot instructions

[Copilot]

Configures GitHub Copilot instructions for the docker-mcp repository following GitHub's best practices for Copilot coding agent.

What This PR Does

Creates .github/copilot-instructions.md with repository-specific guidance to help Copilot understand and work with this codebase's unique patterns and standards.

Key Features

Architecture Patterns: Documents the Consolidated Action-Parameter Pattern used throughout this repository instead of simple @mcp.tool() decorators. This pattern is critical for Docker infrastructure management operations that require orchestration and state management.

Modern Python Standards: Enforces Python 3.11+ syntax including union types (str | None), type aliases, and modern async exception handling patterns that are used consistently across the codebase.

Security Guidelines: Includes Docker command validation, SSH security requirements, and migration safety patterns that are essential for this infrastructure management tool.

Testing & Development: Documents the FastMCP in-memory testing patterns, pytest markers, and uv-based development workflow specific to this project.

Implementation Approach

The instructions were extracted and consolidated from existing documentation (CLAUDE.md, AGENTS.md, pyproject.toml) to maintain consistency while providing Copilot with actionable guidance. This ensures minimal changes while leveraging the extensive documentation already present in the repository.

The file structure mirrors the repository's modular architecture, explaining the service → tool → model layering and hybrid connection model (Docker contexts vs. SSH) that makes this codebase unique.

Fixes #[issue_number]

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

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

• astral.sh
  • Triggering command: curl -LsSf 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)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>✨ Set up Copilot instructions</issue_title>
<issue_description>Configure instructions for this repository as documented in Best practices for Copilot coding agent in your repository.

</issue_description>

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

Fixes #15

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✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.