[P1] Implement command Hook system (command-type)

[xinhuagu]

Goal: provide extensibility hook points for command lifecycle in daemon/CLI flow.

Scope:

• Define hook contract and registration/loading
• Add command lifecycle trigger points
• Add error propagation/logging policy
• Add basic tests for hook invocation order

Dependency:

• Depends on: HealthMonitor/CircuitBreaker foundation (for safe execution and observability).

[xinhuagu]

Implemented in PR #41 (commit 08fe14c). Command hook system is fully functional with pre/post hooks, pattern matching, and timeout support.