Add GitHub Copilot custom agent configurations

[Copilot]

Adds specialized agent configurations in .github/agents/ to provide domain-specific guidance for TypeScript/React development, testing, code review, documentation, and security/compliance.

Agents Added

• typescript-react-agent.yml - Enforces strict typing, mandates reusability checks, references project-specific types/utilities
• testing-agent.yml - Vitest/Cypress patterns, 80% coverage standards, test ID conventions
• code-review-agent.yml - Reusability enforcement, security scanning, type safety verification
• documentation-agent.yml - JSDoc/TypeDoc standards, Mermaid diagrams, C4 architecture docs
• security-compliance-agent.yml - CIA triad principles, NIST/ISO/GDPR framework mapping

Key Features

Each agent references project-specific reusable items:

# Example from typescript-react-agent.yml
- **Types:** src/types/cia.ts, src/types/widgets.ts
- **Constants:** src/constants/securityLevels.ts, src/constants/testIds.ts
- **Utilities:** src/utils/securityLevelUtils.ts, src/utils/riskUtils.ts

All agents enforce v1.0 release priorities (bug fixes/stability only, no new features) and critical reusability checks before creating new code.

Files

• 5 agent YAML configs (653 lines)
• 1 comprehensive README (184 lines)
• All YAML validated

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Add Copilot coding agent instructions</issue_title>
<issue_description></issue_description>

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

• Fixes Add Copilot coding agent instructions #536

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💡 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.

[github-actions]

Dependency Review

✅ No vulnerabilities or license issues or OpenSSF Scorecard issues found.

Scanned Files

None