Subtasks may not display in run dashboard — only main tasks visible

[MatthewLones]

Description

During runs with ClaudeAgentRunner, subtasks (reported by agents via __PROGRESS__.json) may not appear in the TodoWidget. Only the main phase tasks are visible.

Probable Primary Cause: Panel Too Small (#10)

Updated: Issue #10's root cause has been corrected. The task panel auto-expands to only 20% of the PanelGroup (~5% of visible screen), which is far too small to show subtasks below their parent tasks. Subtasks render as indented items below each parent — if the panel is tiny, they're scrolled out of view entirely.

Fixing #10 (increasing auto-expand from resize(20) to resize(35)) should resolve the majority of "missing subtask" reports.

Secondary Causes (verify after #10 fix)

1. Race condition in derive-phase-todos.ts:37-41 — subtasks are only attached to existing TodoItems via:

   const existing = todoMap.get(event.nodeId);
   if (existing) {
     existing.subtasks = event.subtasks;
   }

   If subtask_update arrives before phase_started, the parent doesn't exist in the map yet and subtasks are silently dropped.

2. Conditional rendering in TodoWidget.tsx:135-137 — subtasks only render when the parent task is in_progress or completed. If the parent shows as pending, subtasks are hidden.

Steps to Verify

1. Fix panel height (Run dashboard task panel too small — auto-expand insufficient, can barely resize larger #10) first and re-test — this is most likely the cause
2. If subtasks still missing after Run dashboard task panel too small — auto-expand insufficient, can barely resize larger #10 fix, check browser console for subtask_update SSE events arriving before phase_started
3. Check if __PROGRESS__.json is being written to the agent's output directory

Files Involved

• packages/ui/src/components/shared/TodoWidget.tsx — lines 135-188 (subtask rendering)
• packages/ui/src/lib/derive-phase-todos.ts — lines 37-41 (subtask mapping)
• packages/ui/src/pages/RunDashboardPage.tsx — panel constraints (see Run dashboard task panel too small — auto-expand insufficient, can barely resize larger #10)