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/test-case/TestCaseDetailDrawer.tsx

@@ -1,7 +1,7 @@
 'use client';
 
 import { useState } from 'react';
-import { X, AlertTriangle, Link2, ChevronRight, Bug as BugIcon } from 'lucide-react';
+import { X, AlertTriangle, Link2, ChevronRight, Bug as BugIcon, Trash2 } from 'lucide-react';
 import { TestCaseStatusBadge } from './TestCaseStatusBadge';
 import { BugStatusBadge } from '@/components/bug/BugStatusBadge';
 import { useTestCaseStore } from '@/stores/useTestCaseStore';
@@ -18,7 +18,7 @@ interface Props {
 }
 
 export function TestCaseDetailDrawer({ testCaseId, onClose, onCreateBug }: Props) {
-  const { testCases, changeStatus } = useTestCaseStore();
+  const { testCases, changeStatus, deleteTestCase } = useTestCaseStore();
   const { bugs } = useBugStore();
   const { requirements } = useRequirementStore();
 
@@ -60,7 +60,10 @@ export function TestCaseDetailDrawer({ testCaseId, onClose, onCreateBug }: Props
             <span className="text-[12px] font-mono text-[var(--ink-muted)]">{tc.caseNo}</span>
             <span className="text-[14px] font-semibold text-[var(--ink)] truncate max-w-[240px]">{tc.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 (relatedBugs.length > 0) { alert('该用例有关联 Bug，无法删除'); return; } if (confirm('确定删除此测试用例？')) { deleteTestCase(tc.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>
 
         <div className="flex-1 overflow-y-auto p-4 space-y-3">