perf(renderer): compare kanban task dependencies

src/renderer/components/team/kanban/KanbanTaskCard.test.tsx

@@ -242,6 +242,55 @@ describe('KanbanTaskCard comment badge pulse', () => {
     });
   });
 
+  it('skips rerender when an unrelated taskMap entry changes', async () => {
+    const memberColorMap = new Map([['alice', 'blue']]);
+    const { root } = await renderTaskCard({
+      task: { ...baseTask, blockedBy: [], blocks: [], comments: [] },
+      taskMap: new Map([['other-task', { ...baseTask, id: 'other-task', subject: 'Other task' }]]),
+      memberColorMap,
+    });
+
+    unreadCommentCountMock.calls = 0;
+    await rerenderTaskCard(root, {
+      task: { ...baseTask, blockedBy: [], blocks: [], comments: [] },
+      taskMap: new Map([
+        ['other-task', { ...baseTask, id: 'other-task', subject: 'Updated unrelated task' }],
+      ]),
+      memberColorMap,
+    });
+
+    expect(unreadCommentCountMock.calls).toBe(0);
+
+    await act(async () => {
+      root.unmount();
+      await flushReact();
+    });
+  });
+
+  it('rerenders when a displayed dependency task changes', async () => {
+    const memberColorMap = new Map([['alice', 'blue']]);
+    const blockedTask = { ...baseTask, id: 'dep-1', displayId: 'dep1', subject: 'Dependency A' };
+    const { root } = await renderTaskCard({
+      task: { ...baseTask, blockedBy: ['dep-1'], blocks: [], comments: [] },
+      taskMap: new Map([['dep-1', blockedTask]]),
+      memberColorMap,
+    });
+
+    unreadCommentCountMock.calls = 0;
+    await rerenderTaskCard(root, {
+      task: { ...baseTask, blockedBy: ['dep-1'], blocks: [], comments: [] },
+      taskMap: new Map([['dep-1', { ...blockedTask, subject: 'Dependency B', status: 'done' }]]),
+      memberColorMap,
+    });
+
+    expect(unreadCommentCountMock.calls).toBeGreaterThan(0);
+
+    await act(async () => {
+      root.unmount();
+      await flushReact();
+    });
+  });
+
   it('rerenders when a hidden task field changes so click handlers stay current', async () => {
     const taskMap = new Map();
     const memberColorMap = new Map([['alice', 'blue']]);

src/renderer/components/team/kanban/KanbanTaskCard.tsx

@@ -108,6 +108,44 @@ function areKanbanTaskStatesEqual(
   );
 }
 
+function getTaskDependencyIds(task: TeamTaskWithKanban): string[] {
+  return [...(task.blockedBy ?? []), ...(task.blocks ?? [])].filter((id) => id.length > 0);
+}
+
+function getDependencyTaskSignature(task: TeamTask | undefined): string {
+  if (!task) return '';
+  const kanbanTask = task as Partial<TeamTaskWithKanban>;
+  return [
+    task.id,
+    task.displayId ?? '',
+    task.subject,
+    task.status,
+    task.reviewState ?? '',
+    kanbanTask.kanbanColumn ?? '',
+  ].join('\u001f');
+}
+
+function areTaskMapDependenciesEqual(
+  prevTask: TeamTaskWithKanban,
+  nextTask: TeamTaskWithKanban,
+  prevTaskMap: Map<string, TeamTask>,
+  nextTaskMap: Map<string, TeamTask>
+): boolean {
+  const dependencyIds = new Set([
+    ...getTaskDependencyIds(prevTask),
+    ...getTaskDependencyIds(nextTask),
+  ]);
+  for (const taskId of dependencyIds) {
+    if (
+      getDependencyTaskSignature(prevTaskMap.get(taskId)) !==
+      getDependencyTaskSignature(nextTaskMap.get(taskId))
+    ) {
+      return false;
+    }
+  }
+  return true;
+}
+
 function createCommentPulseState(
   taskKey: string,
   comments: readonly TaskComment[],
@@ -682,7 +720,7 @@ export const KanbanTaskCard = memo(
     areKanbanTaskStatesEqual(prev.kanbanTaskState, next.kanbanTaskState) &&
     prev.hasReviewers === next.hasReviewers &&
     prev.compact === next.compact &&
-    prev.taskMap === next.taskMap &&
+    areTaskMapDependenciesEqual(prev.task, next.task, prev.taskMap, next.taskMap) &&
     prev.memberColorMap === next.memberColorMap &&
     prev.hasLiveTaskLogs === next.hasLiveTaskLogs &&
     prev.onRequestReview === next.onRequestReview &&