feat(优先级)：维度权重可配置并即时重算

- 新表 user_priority_weights（每用户一行，默认 0.35/0.25/0.20/0.10/0.10）
- PriorityWeightsService：读取/保存权重，权重和必须为 1，保存后重算全部任务
- TaskController：GET/PUT /tasks/priority-weights
- CalculatedPriorityTool 支持自定义权重
- 修复 updateTask 不重算优先级的问题

src/main/java/com/guo/learningprogresstracker/service/PriorityWeightsService.java

@@ -0,0 +1,21 @@
+package com.guo.learningprogresstracker.service;
+
+import com.guo.learningprogresstracker.entity.UserPriorityWeightsEntity;
+import com.guo.learningprogresstracker.exception.ErrorParameterException;
+
+/**
+ * 优先级权重配置服务
+ */
+public interface PriorityWeightsService {
+
+    /**
+     * 获取当前用户的权重配置，不存在时返回系统默认值
+     */
+    UserPriorityWeightsEntity getWeights();
+
+    /**
+     * 保存权重配置并重算当前用户全部任务的优先级。
+     * 五项权重之和必须为 1（容差 0.001）。
+     */
+    UserPriorityWeightsEntity saveWeights(UserPriorityWeightsEntity weights) throws ErrorParameterException;
+}

src/main/java/com/guo/learningprogresstracker/service/impl/PriorityWeightsServiceImpl.java

@@ -0,0 +1,99 @@
+package com.guo.learningprogresstracker.service.impl;
+
+import com.baomidou.mybatisplus.core.toolkit.Wrappers;
+import com.guo.learningprogresstracker.dto.PriorityDto;
+import com.guo.learningprogresstracker.entity.TaskEntity;
+import com.guo.learningprogresstracker.entity.UserPriorityWeightsEntity;
+import com.guo.learningprogresstracker.exception.ErrorParameterException;
+import com.guo.learningprogresstracker.mapper.TasksMapper;
+import com.guo.learningprogresstracker.mapper.UserPriorityWeightsMapper;
+import com.guo.learningprogresstracker.service.PriorityWeightsService;
+import com.guo.learningprogresstracker.utils.CalculatedPriorityTool;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.List;
+
+/**
+ * 优先级权重配置服务实现
+ */
+@Slf4j
+@Service
+@RequiredArgsConstructor
+public class PriorityWeightsServiceImpl implements PriorityWeightsService {
+
+    private static final double SUM_TOLERANCE = 0.001;
+
+    private final UserPriorityWeightsMapper weightsMapper;
+    private final TasksMapper tasksMapper;
+
+    @Override
+    public UserPriorityWeightsEntity getWeights() {
+        UserPriorityWeightsEntity existing = weightsMapper.selectOne(
+                Wrappers.<UserPriorityWeightsEntity>lambdaQuery().last("LIMIT 1"));
+        return existing != null ? existing : UserPriorityWeightsEntity.defaults();
+    }
+
+    @Override
+    @Transactional
+    public UserPriorityWeightsEntity saveWeights(UserPriorityWeightsEntity weights) throws ErrorParameterException {
+        validate(weights);
+
+        UserPriorityWeightsEntity existing = weightsMapper.selectOne(
+                Wrappers.<UserPriorityWeightsEntity>lambdaQuery().last("LIMIT 1"));
+        if (existing == null) {
+            weightsMapper.insert(weights);
+        } else {
+            weights.setId(existing.getId());
+            weightsMapper.updateById(weights);
+        }
+
+        recalculateAllTasks(weights);
+        return weights;
+    }
+
+    /** 用新权重重算当前用户的全部任务优先级 */
+    private void recalculateAllTasks(UserPriorityWeightsEntity weights) {
+        List<TaskEntity> tasks = tasksMapper.selectList(Wrappers.lambdaQuery(TaskEntity.class));
+        for (TaskEntity task : tasks) {
+            PriorityDto dto = new PriorityDto();
+            dto.setUrgency(orZero(task.getUrgency()));
+            dto.setImportance(orZero(task.getImportance()));
+            dto.setContentDifficulty(orZero(task.getContentDifficulty()));
+            dto.setFutureValue(orZero(task.getFutureValue()));
+            dto.setSubjectivePriority(orZero(task.getSubjectivePriority()));
+            task.setCalculatedPriority(CalculatedPriorityTool.calculatedPriority(dto, weights));
+            tasksMapper.updateById(task);
+        }
+        log.info("权重更新，已重算 {} 个任务的优先级", tasks.size());
+    }
+
+    private void validate(UserPriorityWeightsEntity weights) throws ErrorParameterException {
+        double[] values = {
+                orZero(weights.getUrgencyWeight()),
+                orZero(weights.getImportanceWeight()),
+                orZero(weights.getContentDifficultyWeight()),
+                orZero(weights.getFutureValueWeight()),
+                orZero(weights.getSubjectivePriorityWeight())};
+        double sum = 0;
+        for (double v : values) {
+            if (v < 0 || v > 1) {
+                throw new ErrorParameterException("权重必须在 0 到 1 之间");
+            }
+            sum += v;
+        }
+        if (Math.abs(sum - 1.0) > SUM_TOLERANCE) {
+            throw new ErrorParameterException("五项权重之和必须为 1，当前为 " + sum);
+        }
+    }
+
+    private static int orZero(Integer v) {
+        return v == null ? 0 : v;
+    }
+
+    private static double orZero(Double v) {
+        return v == null ? 0 : v;
+    }
+}

src/main/java/com/guo/learningprogresstracker/service/impl/TasksServiceImpl.java

@@ -17,6 +17,7 @@ import com.guo.learningprogresstracker.exception.NotFindEntitiesException;
 import com.guo.learningprogresstracker.mapStruct.RequestConvert;
 import com.guo.learningprogresstracker.mapStruct.TaskConvert;
 import com.guo.learningprogresstracker.mapper.TaskApplicationMapper;
+import com.guo.learningprogresstracker.service.PriorityWeightsService;
 import com.guo.learningprogresstracker.service.TasksService;
 import com.guo.learningprogresstracker.mapper.TasksMapper;
 import com.guo.learningprogresstracker.utils.CalculatedPriorityTool;
@@ -42,6 +43,8 @@ public class TasksServiceImpl extends ServiceImpl<TasksMapper, TaskEntity>
 
     private final TaskApplicationMapper taskApplicationMapper;
 
+    private final PriorityWeightsService priorityWeightsService;
+
     @Override
     public Page<TaskInfo> taskList(Integer pageNum, Integer pageSize) {
         Page<TaskEntity> page = tasksMapper.selectPage(new Page<TaskEntity>(pageNum, pageSize),
@@ -62,7 +65,7 @@ public class TasksServiceImpl extends ServiceImpl<TasksMapper, TaskEntity>
 
         task.setTaskNum(GenerateNumTool.generateNum("TASK"));
         PriorityDto priorityDto = RequestConvert.MAPPER.taskRequestToPriorityDto(taskRequest);
-        task.setCalculatedPriority(CalculatedPriorityTool.calculatedPriority(priorityDto));
+        task.setCalculatedPriority(CalculatedPriorityTool.calculatedPriority(priorityDto, priorityWeightsService.getWeights()));
         this.save(task);
         return task.getTaskNum();
     }
@@ -87,6 +90,9 @@ public class TasksServiceImpl extends ServiceImpl<TasksMapper, TaskEntity>
             throw new IllegalArgumentException("任务ID格式错误: " + taskId);
         }
         taskEntity.setId(id);
+        // 维度数据可能变化，更新时重算优先级
+        PriorityDto priorityDto = RequestConvert.MAPPER.taskRequestToPriorityDto(updatedTask);
+        taskEntity.setCalculatedPriority(CalculatedPriorityTool.calculatedPriority(priorityDto, priorityWeightsService.getWeights()));
         this.updateById(taskEntity);
     }