feat: 开发任务时间字段重构 + 双口径耗时 + 搜索 + 性能优化

核心变更:
- DevTask 字段重构：startDate/dueDate/estimateHours/actualHours 替换为 expectedStartAt/expectedEndAt/actualStartAt/actualEndAt（含时分），预计/实际工时按工作时段（9:00-12:00 + 13:00-18:00）派生计算
- 状态机自动化：到点自动切开发中、未到可手动开干、超期需填延后原因
- 新建 lib/work-hours.ts：calcWorkHours（工作时段过滤）、formatWorkHours（X h（Y 天））、calcTwoMetrics（日历/人力双口径）
- 新建 lib/dev-task-transitions.ts：状态切换守卫
- 三个 Tab 顶部统计：开发任务（预/日历/人力）、测试用例 / Bug（日历 / 人力）；版本概览总人天投入改双行（日历总耗时 / 人力总投入）
- 三个 Tab 加搜索框：300ms debounce + 标题/编号模糊匹配
- 性能优化：requirementIds/categories/requirements/testCases 转 Map/Set 索引、Row 组件 React.memo
- 全局耗时显示统一带天数换算：8h（1天）、11h（1.4天）

新增文件: SearchInput.tsx, useDebouncedValue.ts, work-hours.ts, dev-task-transitions.ts, 设计文档

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

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

@@ -1,12 +1,13 @@
 'use client';
 
-import { useState, useMemo } from 'react';
+import { useState, useMemo, useEffect } from 'react';
 import { X, AlertTriangle } from 'lucide-react';
 import { useDevTaskStore } from '@/stores/useDevTaskStore';
 import { useTaskCategoryStore } from '@/stores/useTaskCategoryStore';
 import { useRequirementStore } from '@/stores/useRequirementStore';
 import { useMemberStore } from '@/stores/useMemberStore';
 import { useAuthStore } from '@/stores/useAuthStore';
+import { calcWorkHours, formatWorkHours, isoToLocal, localToISO } from '@/lib/work-hours';
 import type { Priority } from '@/lib/derive';
 
 interface Props {
@@ -17,6 +18,18 @@ interface Props {
   onCreated?: () => void;
 }
 
+function defaultExpectedStart(): string {
+  const d = new Date();
+  d.setHours(9, 0, 0, 0);
+  return isoToLocal(d.toISOString());
+}
+
+function defaultExpectedEnd(): string {
+  const d = new Date();
+  d.setHours(18, 0, 0, 0);
+  return isoToLocal(d.toISOString());
+}
+
 export function DevTaskCreateModal({ versionId, requirementIds, versionDeadline, onClose, onCreated }: Props) {
   const { createTask, tasks } = useDevTaskStore();
   const { categories } = useTaskCategoryStore();
@@ -39,16 +52,46 @@ export function DevTaskCreateModal({ versionId, requirementIds, versionDeadline,
   const [assigneeId, setAssigneeId] = useState(user?.name || '');
   const [priority, setPriority] = useState<Priority>(versionReqs[0]?.priority || 'P2');
   const [priorityManuallySet, setPriorityManuallySet] = useState(false);
-  const [estimateHours, setEstimateHours] = useState<number>(8);
-  const [dueDate, setDueDate] = useState('');
+  const [expectedStartLocal, setExpectedStartLocal] = useState(defaultExpectedStart);
+  const [expectedEndLocal, setExpectedEndLocal] = useState(defaultExpectedEnd);
   const [predecessorIds, setPredecessorIds] = useState<string[]>([]);
   const [description, setDescription] = useState('');
-  const [overdueReason, setOverdueReason] = useState('');
+  const [overdueVersionReason, setOverdueVersionReason] = useState('');
+
+  useEffect(() => {
+    if (categories[0] && !categoryId) setCategoryId(categories[0].id);
+  }, [categories, categoryId]);
+
+  const expectedStartISO = localToISO(expectedStartLocal);
+  const expectedEndISO = localToISO(expectedEndLocal);
+
+  const estimateHours = useMemo(() => {
+    if (!expectedStartISO || !expectedEndISO) return 0;
+    return calcWorkHours(expectedStartISO, expectedEndISO);
+  }, [expectedStartISO, expectedEndISO]);
 
   const selectedReq = versionReqs.find((r) => r.id === requirementId);
   const effectivePriority = priorityManuallySet ? priority : (selectedReq?.priority || priority);
-  const isOverdue = !!(dueDate && versionDeadline && dueDate > versionDeadline);
-  const canSubmit = title.trim() && requirementId && categoryId && assigneeId && estimateHours > 0 && (!isOverdue || overdueReason.trim());
+
+  const versionDeadlineISO = useMemo(() => {
+    if (!versionDeadline) return null;
+    const d = new Date(versionDeadline);
+    if (isNaN(d.getTime())) return null;
+    d.setHours(23, 59, 59, 999);
+    return d.toISOString();
+  }, [versionDeadline]);
+
+  const isOverdueVersion = !!(expectedEndISO && versionDeadlineISO && expectedEndISO > versionDeadlineISO);
+  const startBeforeEnd = expectedStartISO && expectedEndISO && expectedStartISO < expectedEndISO;
+
+  const canSubmit =
+    title.trim() &&
+    requirementId &&
+    categoryId &&
+    assigneeId &&
+    !!startBeforeEnd &&
+    estimateHours > 0 &&
+    (!isOverdueVersion || overdueVersionReason.trim());
 
   const handleSubmit = () => {
     if (!canSubmit) return;
@@ -60,16 +103,17 @@ export function DevTaskCreateModal({ versionId, requirementIds, versionDeadline,
       assigneeId,
       reviewerId: undefined,
       priority: effectivePriority,
-      estimateHours,
-      startDate: undefined,
-      dueDate: dueDate || undefined,
-      completedAt: undefined,
+      expectedStartAt: expectedStartISO,
+      expectedEndAt: expectedEndISO,
+      actualStartAt: undefined,
+      actualEndAt: undefined,
       status: 'todo',
       blockReason: undefined,
       blockedById: undefined,
       predecessorIds: predecessorIds.length > 0 ? predecessorIds : undefined,
       riskLevel: undefined,
-      overdueReason: isOverdue ? overdueReason.trim() : undefined,
+      delayReason: undefined,
+      overdueVersionReason: isOverdueVersion ? overdueVersionReason.trim() : undefined,
       createdBy: user?.name || '系统',
     });
     onCreated?.();
@@ -109,7 +153,17 @@ export function DevTaskCreateModal({ versionId, requirementIds, versionDeadline,
               </select>
             </div>
           </div>
-          <div className="grid grid-cols-3 gap-3">
+          <div className="grid grid-cols-2 gap-3">
+            <div>
+              <label className="block text-[12px] text-[var(--ink-soft)] mb-1">预计开始 *</label>
+              <input type="datetime-local" value={expectedStartLocal} onChange={(e) => setExpectedStartLocal(e.target.value)} className="h-9 w-full rounded-lg border border-[var(--line)] bg-[var(--bg)] px-3 text-[13px] focus:border-[var(--accent)] focus:outline-none" />
+            </div>
+            <div>
+              <label className="block text-[12px] text-[var(--ink-soft)] mb-1">预计截止 *</label>
+              <input type="datetime-local" value={expectedEndLocal} onChange={(e) => setExpectedEndLocal(e.target.value)} className="h-9 w-full rounded-lg border border-[var(--line)] bg-[var(--bg)] px-3 text-[13px] focus:border-[var(--accent)] focus:outline-none" />
+            </div>
+          </div>
+          <div className="grid grid-cols-2 gap-3">
             <div>
               <label className="block text-[12px] text-[var(--ink-soft)] mb-1">优先级</label>
               <select value={effectivePriority} onChange={(e) => { setPriority(e.target.value as Priority); setPriorityManuallySet(true); }} className="h-9 w-full rounded-lg border border-[var(--line)] bg-[var(--bg)] px-3 text-[13px] focus:border-[var(--accent)] focus:outline-none">
@@ -117,24 +171,28 @@ export function DevTaskCreateModal({ versionId, requirementIds, versionDeadline,
               </select>
             </div>
             <div>
-              <label className="block text-[12px] text-[var(--ink-soft)] mb-1">预计工时(h) *</label>
-              <input type="number" min={0.5} step={0.5} value={estimateHours} onChange={(e) => setEstimateHours(parseFloat(e.target.value) || 0)} className="h-9 w-full rounded-lg border border-[var(--line)] bg-[var(--bg)] px-3 text-[13px] focus:border-[var(--accent)] focus:outline-none" />
-            </div>
-            <div>
-              <label className="block text-[12px] text-[var(--ink-soft)] mb-1">截止日期</label>
-              <input type="date" value={dueDate} onChange={(e) => setDueDate(e.target.value)} className="h-9 w-full rounded-lg border border-[var(--line)] bg-[var(--bg)] px-3 text-[13px] focus:border-[var(--accent)] focus:outline-none" />
-              {versionDeadline && (
-                <p className="text-[10px] text-[var(--ink-muted)] mt-0.5">版本截止：{versionDeadline}</p>
-              )}
+              <label className="block text-[12px] text-[var(--ink-soft)] mb-1">预计工时（自动）</label>
+              <div className="h-9 flex items-center px-3 rounded-lg border border-dashed border-[var(--line)] bg-[var(--bg-subtle)] text-[13px] text-[var(--ink-soft)] tabular-nums">
+                {estimateHours > 0 ? formatWorkHours(estimateHours) : (startBeforeEnd ? '0h' : '请先选择有效起止时间')}
+              </div>
+              <p className="text-[10px] text-[var(--ink-muted)] mt-0.5">工作时段 9:00–12:00 + 13:00–18:00，跳过周末</p>
             </div>
           </div>
-          {isOverdue && (
+          {!startBeforeEnd && expectedStartLocal && expectedEndLocal && (
+            <div className="rounded-lg border border-amber-200 bg-amber-50 p-2 text-[11px] text-amber-700">
+              预计开始必须早于预计截止
+            </div>
+          )}
+          {versionDeadline && (
+            <p className="text-[10px] text-[var(--ink-muted)]">版本截止：{versionDeadline}</p>
+          )}
+          {isOverdueVersion && (
             <div className="rounded-lg border border-orange-200 bg-orange-50 p-3 space-y-2">
               <div className="flex items-center gap-1.5 text-[11px] text-orange-700">
                 <AlertTriangle className="h-3.5 w-3.5" />
-                任务截止日期超出版本截止日期（{versionDeadline}），请说明原因
+                任务预计截止超出版本截止日期（{versionDeadline}），请说明原因
               </div>
-              <input value={overdueReason} onChange={(e) => setOverdueReason(e.target.value)} placeholder="超期原因（必填）" className="h-8 w-full rounded-md border border-orange-200 bg-white px-2 text-[12px] focus:border-orange-400 focus:outline-none" />
+              <input value={overdueVersionReason} onChange={(e) => setOverdueVersionReason(e.target.value)} placeholder="超期原因（必填）" className="h-8 w-full rounded-md border border-orange-200 bg-white px-2 text-[12px] focus:border-orange-400 focus:outline-none" />
             </div>
           )}
           {versionTasks.length > 0 && (