feat: add Copilot instructions for repository

[Copilot]

Adds .github/copilot-instructions.md to provide context-aware guidance for GitHub Copilot when assisting with Nitro development.

Changes

• Project context: Framework identity, tech stack (TypeScript/ESM, pnpm, Node >=22, Vite|Rolldown|Rollup)
• Repository structure: src/ organization (build, cli, config, runtime, presets), test hierarchy, docs and examples
• Critical constraints: Runtime code must be platform-agnostic (Web APIs only, no Node.js APIs, minimal bundle size)
• Code conventions: UnJS ecosystem tools (pathe, defu, consola, unstorage), virtual module registration, CLI command structure
• Testing strategy: Regression tests in test/fixture/, type checking, deterministic test requirements
• Contribution guidelines: Minimal targeted changes, dependency considerations, backwards compatibility requirements
• Common patterns: Error handling, preset structure, semantic commits

Sourced from existing CLAUDE.md, AGENTS.md, and CONTRIBUTING.md documentation.

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:

• gh.io
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (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>

<agent_instructions>make sure to use semantic commits</agent_instructions>

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

• Fixes ✨ Set up Copilot instructions #3979

---

💡 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.

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Project	Deployment	Review	Updated (UTC)
nitro.build	Ready	Preview, Comment	Jan 25, 2026 9:22pm