feat: 开发任务和测试用例增加批量删除 + 单条删改

- DevTaskTab: 列表行前增加 checkbox，支持全选/批量删除
- DevTaskDetailDrawer: 顶部增加删除按钮（带确认）
- TestCaseTab: 同上，批量删除时校验关联 Bug（有 Bug 不可删）
- TestCaseDetailDrawer: 顶部增加删除按钮（有关联 Bug 时提示不可删）

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

apps/web/components/dev-task/DevTaskDetailDrawer.tsx

@@ -1,7 +1,7 @@
 'use client';
 
 import { useState } from 'react';
-import { X, AlertTriangle, Link2, ChevronRight, Clock, User, Tag, Calendar, Play } from 'lucide-react';
+import { X, AlertTriangle, Link2, ChevronRight, Clock, User, Tag, Calendar, Play, Trash2, Pencil } from 'lucide-react';
 import { StatusBadge } from './StatusBadge';
 import { CategoryChip } from './CategoryChip';
 import { useDevTaskStore } from '@/stores/useDevTaskStore';
@@ -17,7 +17,7 @@ interface Props {
 }
 
 export function DevTaskDetailDrawer({ taskId, allTaskIds, onClose }: Props) {
-  const { tasks, changeStatus, setBlocked } = useDevTaskStore();
+  const { tasks, changeStatus, setBlocked, deleteTask } = useDevTaskStore();
   const { categories } = useTaskCategoryStore();
   const { requirements } = useRequirementStore();
 
@@ -58,7 +58,10 @@ export function DevTaskDetailDrawer({ taskId, allTaskIds, onClose }: Props) {
             <span className="text-[12px] font-mono text-[var(--ink-muted)]">{task.taskNo}</span>
             <span className="text-[14px] font-semibold text-[var(--ink)] truncate max-w-[240px]">{task.title}</span>
           </div>
-          <button onClick={onClose} className="p-1.5 rounded-lg hover:bg-[var(--bg-subtle)]"><X className="h-4 w-4 text-[var(--ink-muted)]" /></button>
+          <div className="flex items-center gap-1">
+            <button onClick={() => { if (confirm('确定删除此任务？')) { deleteTask(task.id); onClose(); } }} className="p-1.5 rounded-lg hover:bg-red-50 text-[var(--ink-muted)] hover:text-red-500" title="删除"><Trash2 className="h-4 w-4" /></button>
+            <button onClick={onClose} className="p-1.5 rounded-lg hover:bg-[var(--bg-subtle)]"><X className="h-4 w-4 text-[var(--ink-muted)]" /></button>
+          </div>
         </div>
 
         {/* 滚动区域 */}