feat: 任务时效累计计算，支持分钟级精度和工作日计算

backend/src/main/java/com/designhub/entity/DemandType.java

@@ -47,10 +47,10 @@ public class DemandType implements Serializable {
     private Integer unitScoreInt;
 
     /**
-     * 预估工时（小时）
+     * 预估工时（小时，支持小数如0.05表示3分钟）
      */
     @TableField("estimated_hours")
-    private Integer estimatedHours;
+    private BigDecimal estimatedHours;
 
     /**
      * 类型描述

frontend/src/views/CreateTask.vue

@@ -15,6 +15,22 @@
             <span v-if="isAdmin" style="color: #31f08b;">管理员身份，无需积分即可发起任务</span>
             <span v-else>本次任务预估消耗: <strong>{{ estimatedScore }}</strong> 分</span>
           </div>
+          
+          <!-- 时效预估 -->
+          <div v-if="estimatedTotalHours > 0" class="time-estimate">
+            <div class="estimate-item">
+              <span class="estimate-label">累计时效:</span>
+              <span class="estimate-value">{{ formattedEstimatedTime }}</span>
+            </div>
+            <div class="estimate-item">
+              <span class="estimate-label">预计完成:</span>
+              <span class="estimate-value">{{ estimatedDeadline }}</span>
+            </div>
+            <div class="estimate-tip">
+              <Icon name="info" size="xs" style="margin-right: 4px; opacity: 0.6;" />
+              <span>按8小时/工作日计算，超过8小时按整天计算</span>
+            </div>
+          </div>
         </div>
 
         <!-- 任务表单 -->
@@ -884,6 +900,75 @@ const estimatedScore = computed(() => {
   return totalScore
 })
 
+// 计算累计时效（小时）
+const estimatedTotalHours = computed(() => {
+  let totalHours = 0
+  
+  for (const item of formData.taskTypes) {
+    if (item.taskTypeId && item.quantity > 0) {
+      const selectedType = taskTypes.value.find(t => t.id === item.taskTypeId)
+      if (selectedType && selectedType.estimatedHours) {
+        totalHours += selectedType.estimatedHours * item.quantity
+      }
+    }
+  }
+  
+  return totalHours
+})
+
+// 格式化时效显示
+const formattedEstimatedTime = computed(() => {
+  const hours = estimatedTotalHours.value
+  if (hours === 0) return '--'
+  
+  if (hours < 1) {
+    return `${Math.round(hours * 60)}分钟`
+  } else if (hours < 24) {
+    const h = Math.floor(hours)
+    const m = Math.round((hours - h) * 60)
+    return m > 0 ? `${h}小时${m}分钟` : `${h}小时`
+  } else {
+    const days = Math.floor(hours / 24)
+    const remainHours = Math.round(hours % 24)
+    return remainHours > 0 ? `${days}天${remainHours}小时` : `${days}天`
+  }
+})
+
+// 计算预计完成时间（考虑8小时工作制）
+const estimatedDeadline = computed(() => {
+  const totalHours = estimatedTotalHours.value
+  if (totalHours === 0) return '--'
+  
+  const now = new Date()
+  const WORK_HOURS_PER_DAY = 8  // 每天工作8小时
+  
+  // 计算需要多少个工作日
+  let workDays = Math.floor(totalHours / WORK_HOURS_PER_DAY)
+  let remainingHours = totalHours % WORK_HOURS_PER_DAY
+  
+  // 如果超过8小时，按24小时（1天）计算
+  if (totalHours > WORK_HOURS_PER_DAY) {
+    // 超过8小时的部分，每8小时算1个工作日，但日历上是24小时
+    const totalDays = Math.ceil(totalHours / WORK_HOURS_PER_DAY)
+    const deadline = new Date(now.getTime() + totalDays * 24 * 60 * 60 * 1000)
+    return formatDeadline(deadline)
+  } else {
+    // 8小时内，当天完成
+    const deadline = new Date(now.getTime() + totalHours * 60 * 60 * 1000)
+    return formatDeadline(deadline)
+  }
+})
+
+// 格式化截止时间
+const formatDeadline = (date: Date) => {
+  const year = date.getFullYear()
+  const month = String(date.getMonth() + 1).padStart(2, '0')
+  const day = String(date.getDate()).padStart(2, '0')
+  const hour = String(date.getHours()).padStart(2, '0')
+  const minute = String(date.getMinutes()).padStart(2, '0')
+  return `${year}-${month}-${day} ${hour}:${minute}`
+}
+
 // 计算流水线分组
 const pipelineGroups = computed(() => {
   if (formData.taskTypes.length === 0) {
@@ -1621,6 +1706,44 @@ onUnmounted(() => {
 
   strong {
     color: $brand-primary;
+  }
+}
+
+.time-estimate {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: $space-md;
+  margin-top: $space-md;
+  padding: $space-md;
+  background: rgba(255, 255, 255, 0.03);
+  border-radius: $radius-small;
+  border: 1px solid rgba(255, 255, 255, 0.06);
+
+  .estimate-item {
+    display: flex;
+    align-items: center;
+    gap: $space-xs;
+    
+    .estimate-label {
+      color: $text-tertiary;
+      font-size: $font-size-sm;
+    }
+    
+    .estimate-value {
+      color: $brand-primary;
+      font-weight: 600;
+      font-size: $font-size-base;
+    }
+  }
+
+  .estimate-tip {
+    flex-basis: 100%;
+    display: flex;
+    align-items: center;
+    font-size: $font-size-xs;
+    color: $text-tertiary;
+    margin-top: $space-xs;
     font-weight: $font-weight-semibold;
   }
 }

frontend/src/views/Settings.vue

@@ -1265,14 +1265,19 @@
             </a-form-item>
             
             <!-- 预计时长（二级和三级分类都可以设置） -->
-            <a-form-item v-if="formData.demandType.addLevel === 'level2' || formData.demandType.addLevel === 'level3'" label="预计时长(小时)">
+            <a-form-item v-if="formData.demandType.addLevel === 'level2' || formData.demandType.addLevel === 'level3'" label="单个任务耗时(小时)">
               <a-input-number
                 v-model:value="formData.demandType.estimatedHours"
                 :min="0"
-                :precision="1"
+                :precision="2"
+                :step="0.05"
                 style="width: 100%"
-                placeholder="请输入预计时长"
+                placeholder="单个任务耗时（如0.05=3分钟，1=1小时）"
               />
+              <div class="form-tip">
+                <Icon name="info" size="sm" color="#6B6B6B" style="margin-right: 4px;" />
+                时效会根据任务数量累计计算（如5个任务×0.05小时=0.25小时）
+              </div>
             </a-form-item>
             
             <a-form-item label="描述">