feat(dev-task): 开发任务模块 V1 完整实现

- 核心库：dev-task.ts（类型+状态机+进度计算）、task-worklog.ts（工时）、task-category.ts（字典）、work-item.ts（聚合契约）
- Store：useDevTaskStore（CRUD+状态流转）、useTaskWorklogStore（工时记录）、useTaskCategoryStore（字典管理）
- UI组件：DevTaskTab、DevTaskCreateModal、DevTaskDetailDrawer、DevTaskRow、WorklogPanel、StatusBadge、CategoryChip
- 集成：版本详情页"开发任务"Tab、"与我相关"工作台开发任务分组、任务类型管理页
- 设计文档：spec + 实施计划

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/lib/work-item.ts

@@ -0,0 +1,49 @@
+import type { DevTask } from './dev-task';
+import type { VersionPlan } from './version-plan';
+import type { Priority } from './derive';
+
+export type WorkItemEntityType = 'plan' | 'devTask' | 'testCase' | 'bug';
+
+export interface WorkItem {
+  entityType: WorkItemEntityType;
+  entityId: string;
+  title: string;
+  status: string;
+  isBlocked?: boolean;
+  assigneeId: string;
+  reviewerId?: string;
+  versionId: string;
+  versionName?: string;
+  priority?: Priority;
+  dueDate?: string;
+  categoryLabel?: string;
+}
+
+export function planToWorkItem(plan: VersionPlan): WorkItem {
+  return {
+    entityType: 'plan',
+    entityId: plan.id,
+    title: plan.title,
+    status: plan.status,
+    assigneeId: plan.owner,
+    versionId: plan.versionId,
+    dueDate: plan.endTime.slice(0, 10),
+    categoryLabel: plan.type === 'research' ? '调研' : plan.type === 'product' ? '产品方案' : 'UI设计',
+  };
+}
+
+export function devTaskToWorkItem(task: DevTask, versionId: string, categoryLabel?: string): WorkItem {
+  return {
+    entityType: 'devTask',
+    entityId: task.id,
+    title: task.title,
+    status: task.status,
+    isBlocked: task.isBlocked,
+    assigneeId: task.assigneeId,
+    reviewerId: task.reviewerId,
+    versionId,
+    priority: task.priority,
+    dueDate: task.dueDate,
+    categoryLabel,
+  };
+}