Add comprehensive test suite for Hands framework:
TestHandRegistry:
- Load all Hands from directory
- Get Hand by name (with not-found handling)
- Get scheduled vs all Hands
- State management (status updates)
- Approval queue operations
TestHandScheduler:
- Scheduler initialization
- Schedule Hand with cron
- Get scheduled jobs list
- Manual trigger execution
TestHandRunner:
- Load system prompts from SYSTEM.md
- Load skills from skills/ directory
- Build execution prompts
TestHandConfig:
- HandConfig creation and validation
- Cron schedule validation
TestHandModels:
- HandStatus enum values
- HandState serialization to dict
17 tests total, all passing.
