Epic verification flow: require human review before closing epics

Epics need more verification before they are closed. Currently they auto-transition to Review when all children complete, but there's no mechanism to ensure the major features were actually shipped and work well.

Current Flow

1. All child tasks → Done 2. Epic auto-transitions to Review (checkEpicCompletion in Jr.hs) 3. No clear path to Done with verification

Proposed Flow

1. All child tasks → Done 2. Epic auto-transitions to Review (keep this) 3. Human reviews the epic on web UI:

• Sees summary of completed work
• Sees any comments/notes from agents
• Can test the features

4. Human clicks Approve → moves to Approved 5. Human clicks Done → closes epic OR 6. Human rejects → reopens with feedback

Key Components

• Epic detail page with verification UI (subtask)
• Summary comment generation when children complete (needs llm, subtask)
• Agent review comments visible on epics (subtask)
• Human review workflow in web UI (subtask)

This is a HumanTask at the epic level - we need human design input on the exact UX.