feat: Add full-fledged built-in orchestrator (evidence-gated conductor)

[gidich]

This PR introduces a permanent, full-fledged orchestrator for continuous development in OpenClinXR.

What was added

• New packages/orchestrator/ with a central Conductor class
• Evidence gate checking that reads from your existing .agent-factory/ reports (risk-report, evidence-debt-report, etc.)
• Role-based agent routing that maps to your existing agents/leadership, agents/physicians, agents/adversarial, etc.
• Continuous loop that can run nonstop via pnpm orchestrator:start
• Designed to respect your evidence-gated philosophy while enabling autonomous development

This removes the dependency on external tools like Superpowers/Codex plugins. The orchestrator is now part of the codebase and can be extended with real LLM integration (Mastra, LangGraph, etc.) later.

How to run

pnpm install
pnpm orchestrator:start

The system will continuously:

1. Check evidence gates from .agent-factory/
2. Pick the next high-priority task
3. Route it to the appropriate specialized agent
4. Execute workflow phases
5. Loop

This is a solid foundation. We can expand the actual LLM calling, task backlog parsing, and agent implementations in follow-up work.