feat: focus daemon on OpenClaw/MCP monitoring

Refocus the daemon on what matters for open-source users: detecting
running AI agents, monitoring OpenClaw skill integrity, and tracking
MCP config drift.

- Rewrite daemon runner for focused monitoring loop
- Remove enterprise modules (behavioral-baseline, correlation-engine,
  cost-monitor, enforcement, event-receiver, fleet)
- Remove related tests
- Keep core: agent detection, OpenClaw drift, signal handling

Author: JBAhire