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/controller/TaskController.java

@@ -11,8 +11,10 @@ import com.guo.learningprogresstracker.entity.CommonResult;
 import com.guo.learningprogresstracker.dto.request.TaskRequest;
 import com.guo.learningprogresstracker.dto.request.UpdateTaskApplicationRequest;
 import com.guo.learningprogresstracker.entity.TaskApplicationEntity;
+import com.guo.learningprogresstracker.entity.UserPriorityWeightsEntity;
 import com.guo.learningprogresstracker.exception.ErrorParameterException;
 import com.guo.learningprogresstracker.exception.NotFindEntitiesException;
+import com.guo.learningprogresstracker.service.PriorityWeightsService;
 import com.guo.learningprogresstracker.service.TasksService;
 import com.guo.learningprogresstracker.service.impl.StudySessionsServiceImpl;
 import io.swagger.v3.oas.annotations.Operation;
@@ -48,6 +50,21 @@ public class TaskController {
 
     private final StudySessionsServiceImpl studySessionsServiceImpl;
 
+    private final PriorityWeightsService priorityWeightsService;
+
+    @GetMapping("/priority-weights")
+    @Operation(summary = "获取优先级维度权重配置")
+    public CommonResult<UserPriorityWeightsEntity> getPriorityWeights() {
+        return CommonResult.success(priorityWeightsService.getWeights());
+    }
+
+    @PutMapping("/priority-weights")
+    @Operation(summary = "保存优先级维度权重配置并重算全部任务优先级")
+    public CommonResult<UserPriorityWeightsEntity> savePriorityWeights(
+            @RequestBody UserPriorityWeightsEntity weights) throws ErrorParameterException {
+        return CommonResult.success(priorityWeightsService.saveWeights(weights));
+    }
+
     @PostMapping
     @Operation(summary = "添加新任务")
     public CommonResult<String> addTask(@RequestBody @Validated({Ops.CreateG.class}) TaskRequest taskRequest) throws ErrorParameterException {