✨ Add Copilot instructions

[Copilot]

Configure GitHub Copilot coding agent instructions following documented best practices.

Changes

• Added .github/copilot-instructions.md - Repository-wide Copilot instructions covering:
  • Development workflow (setup, commands, testing)
  • Code conventions (TypeScript strict mode, Biome linting, inline route components)
  • Security boundaries (HTTPS-only, SSRF protection, rate limiting, no tracking)
  • Architecture patterns (offline-first sync, TypeBox validation)
  • Common task recipes (adding routes, API endpoints, styling, database changes)

Complements existing AGENTS.md (technical architecture) with Copilot-specific guidelines (workflow and conventions).

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>

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

• Fixes ✨ Set up Copilot instructions #2

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