Create unit tests for lib/actions.ts:

• Test delegateTask(): correct assignee updates, notification side-effects
• Test requestReview(): review state transitions, label mapping
• Test validateStatusTransition(): edge cases (from→to for all combos)
• Test breakTaskChain(): correct branching, project association
• Test task file write/read round-trip with mock workspace
• Test body length validation (>10 char constraint)

Location: tests/actions-core.test.ts