## Feature 001: Start and complete a focus session

**Sources:** start-and-complete-a-focus-session
**Personas:** Knowledge Worker seeking distraction-free work blocks
**Stack span:** full-stack
**Tier:** v1

**Description:**

User can initiate a timed focus block, work uninterrupted, and mark it complete when the timer ends.

**Constituent tickets:**
- start-and-complete-a-focus-session
