## Feature 004: Customize session and break durations

**Sources:** customize-session-and-break-lengths, trust-the-app-to-retain-data-across-sessions
**Personas:** user with non-standard work rhythm, power user optimizing for their context
**Stack span:** full-stack
**Tier:** v1

**Description:**

User can adjust the length of work sessions and breaks to fit their workflow, with settings persisted across app restarts.

**Constituent tickets:**
- ticket-011-settings-ui-controls
- ticket-012-duration-validation-logic
- ticket-013-settings-persistence
- ticket-014-apply-settings-to-active-session
