## Feature 001: Start, run, and complete a focus session with timer notification

**Sources:** start-and-complete-a-focus-session
**Personas:** knowledge worker seeking uninterrupted focus time
**Stack span:** full-stack
**Tier:** v1

**Description:**

A user can begin a timed focus session, receive a notification when the session ends, and see it logged in history.

**Constituent tickets:**
- ticket-001-start-and-complete-a-focus-session
