feat: agent platform initial commit

- FastAPI + HTMX UI: dashboard, agents CRUD, chat, audit, tools
- SQLite schema: agents, conversations, messages, audit, sessions
- Code-agent sync (agents/*.py -> DB on startup)
- MCP client with health check
- Token auth (Bearer + session)
- LiteLLM integration via llm.py
- Docker Compose: agent-platform + mcp-tools services
- Smoke tests pass: /health 200, /api/agents 200, / 401

.gitignore

@@ -0,0 +1,7 @@
+__pycache__/
+*.pyc
+*.db
+.venv/
+.env
+*.log
+.pytest_cache/