feat(FN-3889): add bulk delete with dependency conflict detection to ListVi

Bulk delete in ListView is now complete with dependency conflict detection and user-facing recovery options, backed by shared utility logic and tests. The feature touched ListView's core behavior, companion tests, and a small changeset documenting the user-facing recovery behavior.

Fusion-Task-Id: FN-3889

packages/dashboard/app/utils/taskDelete.ts

@@ -0,0 +1,21 @@
+export interface DependencyDeleteConflict {
+  dependentIds: string[];
+}
+
+export function extractDependencyDeleteConflict(err: unknown): DependencyDeleteConflict | null {
+  if (!(err instanceof Error)) {
+    return null;
+  }
+
+  const details = (err as { details?: { code?: string; dependentIds?: unknown } }).details;
+  if (details?.code === "TASK_HAS_DEPENDENTS" && Array.isArray(details.dependentIds)) {
+    return { dependentIds: details.dependentIds.filter((id): id is string => typeof id === "string") };
+  }
+
+  const idsInMessage = err.message.match(/[A-Z]+-\d+/g) ?? [];
+  if (idsInMessage.length > 1) {
+    return { dependentIds: [...new Set(idsInMessage.slice(1))] };
+  }
+
+  return null;
+}