Add comprehensive GitHub Copilot instructions for development workflow

[Copilot]

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

What's Included

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

Validated Commands & Timing

• Dependencies: npm install (3 minutes initial, 15 seconds subsequent)
• Build: npm run build (30 seconds with expected font provider warnings)
• Testing: npm test (15 seconds, 83 tests pass)
• Development: npm run dev (starts successfully with mock data)
• Linting: npm run lint (3 seconds, documents 43 existing errors)
• Type checking: npm run typecheck (9 seconds, documents 18 existing TypeScript errors)

Critical Features

• NEVER CANCEL warnings with explicit timeout recommendations for all time-consuming operations
• Environment configuration requirements including mandatory NUXT_SESSION_PASSWORD
• Mock data testing scenarios that work without GitHub tokens
• Health endpoint validation procedures (/api/health, /api/ready, /api/live)
• Known limitations and existing issues clearly documented

Manual Validation Scenarios

The instructions include specific test scenarios for:

• Health check endpoints functionality
• Mock data dashboard verification at different scopes (orgs, enterprises, teams)
• Build and test workflow validation
• Common development task verification

Technical Details

• Documents the Nuxt 3 + Vue.js + TypeScript + Vuetify stack
• Explains font provider connection warnings as non-blocking
• Covers Docker support limitations in restricted environments
• Provides troubleshooting guidance for common issues

All commands and scenarios have been thoroughly tested and validated to ensure the instructions work reliably for any developer starting fresh with the repository.

Fixes #246.

Warning

Firewall rules blocked me from connecting to one or more addresses

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

• api.fontshare.com
  • Triggering command: node /home/REDACTED/work/copilot-metrics-viewer/copilot-metrics-viewer/node_modules/.bin/nuxt build (dns block)
  • Triggering command: node (vitest) (dns block)
  • Triggering command: /usr/local/bin/node --enable-source-maps /home/REDACTED/work/copilot-metrics-viewer/copilot-metrics-viewer/node_modules/@nuxt/cli/bin/nuxi.mjs _dev (dns block)
• api.fontsource.org
  • Triggering command: node /home/REDACTED/work/copilot-metrics-viewer/copilot-metrics-viewer/node_modules/.bin/nuxt build (dns block)
  • Triggering command: node (vitest) (dns block)
  • Triggering command: /usr/local/bin/node --enable-source-maps /home/REDACTED/work/copilot-metrics-viewer/copilot-metrics-viewer/node_modules/@nuxt/cli/bin/nuxi.mjs _dev (dns block)
• fonts.bunny.net
  • Triggering command: node /home/REDACTED/work/copilot-metrics-viewer/copilot-metrics-viewer/node_modules/.bin/nuxt build (dns block)
  • Triggering command: /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)
  • Triggering command: node (vitest) (dns block)
• fonts.google.com
  • Triggering command: node /home/REDACTED/work/copilot-metrics-viewer/copilot-metrics-viewer/node_modules/.bin/nuxt build (dns block)
  • Triggering command: node (vitest) (dns block)
  • Triggering command: /usr/local/bin/node --enable-source-maps /home/REDACTED/work/copilot-metrics-viewer/copilot-metrics-viewer/node_modules/@nuxt/cli/bin/nuxi.mjs _dev (dns block)
• fonts.googleapis.com
  • Triggering command: node (vitest 1) (dns block)
  • Triggering command: node (vitest 2) (dns block)
  • Triggering command: node (vitest 3) (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)

---

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