# Track Specification: Pipeline Pause/Resume (pipeline_pause_resume_20260306)

## Overview
Add global pause/resume for entire DAG execution pipeline. Allow user to freeze all worker activity and resume later.

## Architectural Constraints
- **State Preservation**: Worker state MUST be preserved across pause.
- **Atomic Operation**: Pause/Resume MUST be atomic.

## Functional Requirements
- **Pause Button**: Freeze all worker activity.
- **Resume Button**: Continue from paused state.
- **Visual Indicator**: Show pipeline is paused.
- **State Display**: Show which workers are paused.

## Acceptance Criteria
- [ ] Pause button freezes pipeline.
- [ ] Resume button continues execution.
- [ ] Visual indicator shows paused state.
- [ ] Worker states preserved.
- [ ] No data loss on resume.