feat: P2+P3 薪酬模板驱动计算 - SYSTEM注册表 + 前端动态化

P2: 社保/公积金/个税改为 SYSTEM 注册表驱动
- 新增 SystemCalcContext 和 systemCalculators 注册表
- ensureSocialHousingCalculated 缓存社保公积金计算
- calcTaxSystem 提取个税计算为系统函数
- calcBatchEntry 重构为模板拓扑排序调度

P3: 前端批次表格动态化 + 模板编辑器增强
- 后端模板 CRUD 支持 calcType/dependencies 字段
- TemplateTab 表格增加计算方式列
- TemplateTab 编辑表单增加 calcType 选择(公式/系统)
- BatchTab editableFields 从模板 isEditable 动态获取

frontend/src/pages/money/BatchTab.tsx

@@ -497,6 +497,13 @@ function BatchDetail({ batchId, onBack }: { batchId: string; onBack: () => void
     },
   })
 
+  const { data: templateItems } = useQuery<any[]>({
+    queryKey: ['payslip-template'],
+    queryFn: async () => {
+      return await payrollApi.template()
+    },
+  })
+
   const updateEntryMutation = useMutation({
     mutationFn: ({ employeeId, data }: { employeeId: string; data: any }) =>
       payrollApi.updateBatchEntry(batchId, employeeId, data),
@@ -729,10 +736,19 @@ function BatchDetail({ batchId, onBack }: { batchId: string; onBack: () => void
     }
   }
 
-  // 可编辑的输入项字段
-  const editableFields = isBonus
-    ? ['bonus']
-    : ['baseSalary', 'performanceSalary', 'overtimePay', 'allowance', 'deduction', 'bonus', 'socialEmp', 'housingEmp', 'socialOrg', 'housingOrg']
+  // 可编辑的输入项字段：从模板动态获取，回退到硬编码
+  const editableFields = (() => {
+    if (templateItems && templateItems.length > 0) {
+      const editable = templateItems.filter((i: any) => i.isEditable).map((i: any) => i.code)
+      // 奖金批次只允许编辑 bonus
+      if (isBonus) return ['bonus']
+      // 社保/公积金允许手动覆盖
+      return [...editable, 'socialEmp', 'housingEmp', 'socialOrg', 'housingOrg']
+    }
+    return isBonus
+      ? ['bonus']
+      : ['baseSalary', 'performanceSalary', 'overtimePay', 'allowance', 'deduction', 'bonus', 'socialEmp', 'housingEmp', 'socialOrg', 'housingOrg']
+  })()
 
   // 点击单元格进入编辑
   const startEdit = (employeeId: string, field: string, currentValue: number) => {

frontend/src/pages/money/TemplateTab.tsx

@@ -23,6 +23,7 @@ export function TemplateManager() {
     code: '',
     type: 'INPUT' as 'INPUT' | 'CALCULATED',
     formula: '',
+    calcType: 'FORMULA' as 'FORMULA' | 'SYSTEM',
     order: 99,
     isEditable: true,
   })
@@ -67,7 +68,7 @@ export function TemplateManager() {
   /** 打开新增表单 */
   const handleAdd = () => {
     setEditingItem(null)
-    setForm({ name: '', code: '', type: 'INPUT', formula: '', order: items?.length ? items.length + 1 : 99, isEditable: true })
+    setForm({ name: '', code: '', type: 'INPUT', formula: '', calcType: 'FORMULA', order: items?.length ? items.length + 1 : 99, isEditable: true })
     setShowForm(true)
   }
 
@@ -79,6 +80,7 @@ export function TemplateManager() {
       code: item.code,
       type: item.type,
       formula: item.formula || '',
+      calcType: item.calcType || 'FORMULA',
       order: item.order,
       isEditable: item.isEditable,
     })
@@ -91,10 +93,11 @@ export function TemplateManager() {
       toast.error('名称和字段代码不能为空')
       return
     }
-    const payload = {
+    const payload: any = {
       name: form.name.trim(),
       type: form.type,
       formula: form.type === 'CALCULATED' ? form.formula.trim() || null : null,
+      calcType: form.type === 'CALCULATED' ? form.calcType : 'FORMULA',
       order: Number(form.order),
       isEditable: form.isEditable,
     }
@@ -128,6 +131,7 @@ export function TemplateManager() {
                   <th className="py-2 px-2 w-24">名称</th>
                   <th className="py-2 px-2 w-32">字段代码</th>
                   <th className="py-2 px-2 w-20">类型</th>
+                  <th className="py-2 px-2 w-24">计算方式</th>
                   <th className="py-2 px-2 w-48">计算公式</th>
                   <th className="py-2 px-2 w-16">可编辑</th>
                   <th className="py-2 px-2 text-right w-24">操作</th>
@@ -144,6 +148,13 @@ export function TemplateManager() {
                         {item.type === 'INPUT' ? '输入项' : '计算项'}
                       </span>
                     </td>
+                    <td className="py-2 px-2">
+                      {item.type === 'CALCULATED' && (
+                        <span className={`px-2 py-0.5 rounded text-xs whitespace-nowrap ${(item.calcType || 'FORMULA') === 'SYSTEM' ? 'bg-amber-50 text-amber-600' : 'bg-teal-50 text-teal-600'}`}>
+                          {(item.calcType || 'FORMULA') === 'SYSTEM' ? '系统计算' : '公式计算'}
+                        </span>
+                      )}
+                    </td>
                     <td className="py-2 px-2 text-gray-500 font-mono text-xs max-w-48 truncate" title={item.formula || ''}>{item.formula || '—'}</td>
                     <td className="py-2 px-2">
                       <span className={`text-xs ${item.isEditable ? 'text-safe' : 'text-gray-500'}`}>
@@ -240,15 +251,36 @@ export function TemplateManager() {
                 </div>
               </div>
               {form.type === 'CALCULATED' && (
-                <div>
-                  <Label>计算公式</Label>
-                  <Input
-                    type="text"
-                    value={form.formula}
-                    onChange={(e) => setForm({ ...form, formula: e.target.value })}
-                    placeholder="如：baseSalary + overtimePay + allowance - deduction"
-                  />
-                  <p className="text-xs text-gray-500 mt-1">可引用其他字段代码进行加减乘除运算</p>
+                <div className="space-y-2">
+                  <div>
+                    <Label>计算方式</Label>
+                    <Select
+                      value={form.calcType}
+                      onChange={(e) => setForm({ ...form, calcType: e.target.value as 'FORMULA' | 'SYSTEM' })}
+                      disabled={!!editingItem && editingItem.isDefault}
+                    >
+                      <option value="FORMULA">公式计算（加减乘除表达式）</option>
+                      <option value="SYSTEM">系统计算（社保/公积金/个税等）</option>
+                    </Select>
+                    {editingItem && editingItem.isDefault && (
+                      <p className="text-xs text-gray-500 mt-1">预置项的计算方式不可修改</p>
+                    )}
+                  </div>
+                  <div>
+                    <Label>{form.calcType === 'SYSTEM' ? '系统函数标识' : '计算公式'}</Label>
+                    <Input
+                      type="text"
+                      value={form.formula}
+                      onChange={(e) => setForm({ ...form, formula: e.target.value })}
+                      placeholder={form.calcType === 'SYSTEM' ? '如：SOCIAL_EMP' : '如：baseSalary + overtimePay + allowance - deduction'}
+                      disabled={!!editingItem && editingItem.isDefault && form.calcType === 'SYSTEM'}
+                    />
+                    <p className="text-xs text-gray-500 mt-1">
+                      {form.calcType === 'SYSTEM'
+                        ? '系统计算标识：SOCIAL_EMP（个人社保）、HOUSING_EMP（个人公积金）、TAX（个税）'
+                        : '可引用其他字段代码进行加减乘除运算，支持 min()、max()、round() 函数'}
+                    </p>
+                  </div>
                 </div>
               )}
               <div>