feat: add OAC commands and login endpoint example

[imatthewtanner]

Summary

This PR adds OpenAgents Control (OAC) workflow commands and a login endpoint example demonstrating OAC standards.

Changes

OAC Commands (6 files)

• \�rainstorm.md\ - Brainstorming workflow command
• \debug.md\ - Debugging workflow command
• \install-context.md\ - Context installation command
• \oac-cleanup.md\ - Cleanup temporary files command
• \oac-help.md\ - OAC usage guide command
• \oac-status.md\ - Plugin status check command

Login Endpoint Example (6 files)

Demonstrates OAC workflow and standards:

• \ ypes.ts\ - Explicit TypeScript interfaces (no \�ny)
• \�alidation.ts\ - Zod schema validation at boundaries
• \�uth-service.ts\ - Pure functions for authentication
• \login-handler.ts\ - Framework-agnostic HTTP handler
• \login.test.ts\ - Unit tests for all pure functions
• \README.md\ - Documentation showing OAC standards applied

Standards Applied

✅ Pure functions (no side effects)
✅ Input validation at boundaries
✅ Secure error handling
✅ Dependency injection
✅ Small functions (< 50 lines)
✅ Explicit TypeScript types
✅ Comprehensive test coverage

Testing

All functions are pure and have unit tests. The login endpoint example follows functional programming patterns and security best practices as defined in the OAC context standards.