feat(HAI-065): add file-scope overlap detection with blockedBy tracking

- Add blockedBy field to Task type and core store
- Update scheduler to set blockedBy when deferring tasks due to file-scope overlap
- Render file-scope overlap badge on TaskCard in dashboard
- Add tests for blockedBy store logic, scheduler deferral, and TaskCard badge
- Simplify and refactor existing executor, triage, and CLI command code

packages/dashboard/app/styles.css

@@ -315,6 +315,35 @@ html, body {
   box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
 }
 
+.card-scope-badge {
+  display: inline-flex;
+  align-items: center;
+  gap: 3px;
+  font-size: 11px;
+  color: var(--in-progress);
+  position: relative;
+  cursor: default;
+}
+
+.card-scope-badge[data-tooltip]:hover::after {
+  content: attr(data-tooltip);
+  position: absolute;
+  bottom: 100%;
+  left: 50%;
+  transform: translateX(-50%);
+  background: var(--bg-card);
+  color: var(--text);
+  border: 1px solid var(--border);
+  border-radius: 6px;
+  padding: 4px 8px;
+  font-size: 11px;
+  white-space: nowrap;
+  z-index: 10;
+  pointer-events: none;
+  margin-bottom: 4px;
+  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
+}
+
 .card-progress {
   display: flex;
   align-items: center;