Add Copilot instructions for repository onboarding

[Copilot]

Adds .github/copilot-instructions.md to provide GitHub Copilot coding agents with essential repository context per best practices.

Contents

• Tech stack: Vue 3 component library, TypeScript, Vite, Tailwind, Yarn
• Commands: All build/test/dev commands with validated parameters (e.g., yarn install --frozen-lockfile, not npm)
• Project structure: Component locations, data-fetching composables, configuration files
• CI/CD: Test workflow (Node 22, Yarn) and publish workflow (Node 20, npm) behavior
• Known issues: Pre-existing TypeScript errors in src/mocks/, expected test warnings
• Development workflow: Pre-commit hooks (Prettier on JS/Vue), lint-staged (also CSS/MD)

All commands were verified working. Type-check has documented pre-existing errors that should not block PRs.

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:

• example.com
  • Triggering command: /usr/local/bin/node /usr/local/bin/node --conditions development --conditions node /home/REDACTED/work/frappe-ui/frappe-ui/node_modules/tinypool/dist/entry/process.js (dns block)
• 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>

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

• Fixes ✨ Set up Copilot instructions #535

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