docs: restructure documentation for improved clarity and navigation

Reorganize documentation into user-focused, developer-focused, and deployment-focused sections.

**New structure:**
- Root: README.md (streamlined), QUICK_START.md, API_REFERENCE.md
- docs/user-guide/: configuration, API usage, integrations, troubleshooting
- docs/developer/: contributing, development setup, testing, architecture
- docs/deployment/: Docker deployment, production checklist, monitoring
- docs/reference/: environment variables, MCP tools, data formats

**Changes:**
- Streamline README.md from 831 to 469 lines
- Create QUICK_START.md for 5-minute onboarding
- Create API_REFERENCE.md as single source of truth for API
- Remove 9 outdated specification docs (v0.2.0 API design)
- Remove DOCKER_API.md (content consolidated into new structure)
- Remove docs/plans/ directory with old design documents
- Update CLAUDE.md with documentation structure guide
- Remove orchestration-specific references

**Benefits:**
- Clear entry points for different audiences
- No content duplication
- Better discoverability through logical hierarchy
- All content reflects current v0.3.0 API

docs/deployment/production-checklist.md

@@ -0,0 +1,50 @@
+# Production Deployment Checklist
+
+Pre-deployment verification.
+
+---
+
+## Pre-Deployment
+
+- [ ] API keys configured in `.env`
+- [ ] Environment variables reviewed
+- [ ] Model configuration validated
+- [ ] Port availability confirmed
+- [ ] Volume mounts configured
+- [ ] Health checks enabled
+- [ ] Restart policy set
+
+---
+
+## Testing
+
+- [ ] `bash scripts/validate_docker_build.sh` passes
+- [ ] `bash scripts/test_api_endpoints.sh` passes
+- [ ] Health endpoint responds correctly
+- [ ] Sample simulation completes successfully
+
+---
+
+## Monitoring
+
+- [ ] Log aggregation configured
+- [ ] Health check monitoring enabled
+- [ ] Alerting configured for failures
+- [ ] Database backup strategy defined
+
+---
+
+## Security
+
+- [ ] API keys stored securely (not in code)
+- [ ] `.env` excluded from version control
+- [ ] Network access restricted
+- [ ] SSL/TLS configured (if exposing publicly)
+
+---
+
+## Documentation
+
+- [ ] Runbook created for operations team
+- [ ] Escalation procedures documented
+- [ ] Recovery procedures tested