Add strategy-agent MVP (FastAPI + Docker + examples)

[asotogrande]

What does this PR change?

Adds Strategy & Feedback Agent (SFA) MVP microservice.

Which module?

-strategy-agent-api-mvp

• Docker-first runnable service (FastAPI + Uvicorn) on port 8010
• Endpoints:
  • GET /health
  • POST /recommend
  • POST /counterfactual
  • POST /brief
• Returns structured fields (recommendations, drivers, assumptions, evidence[]), not only free text
• Includes “golden” request/response JSONs for orchestrator integration tests:
  • modules/strategy-agent/examples/*

How to run (Docker)

From repo root:

docker build -t ops-strategy-agent modules/strategy-agent
docker run --rm -p 8010:8010 ops-strategy-agent


## Checklist
- [ ] README updated (how to run + demo)
- [ ] Inputs/outputs documented
- [ ] No credentials / private data