feat(task): add "only incomplete" filter

Adds a checkbox to the TaskView filter panel that, when checked,
attaches completion_percent_lte=99 to the /api/tasks/ query — i.e.
tasks with completion_percent < 100% (not_started + in_progress).

Bug fix: TaskView.fetchTasks built its query inline and bypassed
useTaskFilters.toApiParams(), so any future field added to the
composable's params mapping would silently no-op. Route the call
through toApiParams() to make the composable the single source of
truth.

Coverage: extend useTaskFilters.spec toApiParams suite with both
branches of onlyIncomplete.
Co-Authored-By: Claude <noreply@anthropic.com>

src/__tests__/composables/useTaskFilters.spec.js

@@ -200,4 +200,21 @@ describe('toApiParams', () => {
       story_id: null,
     })
   })
+
+  it('attaches completion_percent_lte=99 when onlyIncomplete is set', () => {
+    const f = useTaskFilters(refs)
+    f.filters.value.onlyIncomplete = true
+    expect(f.toApiParams()).toEqual({
+      student_id: null,
+      subject_id: null,
+      term_id: null,
+      story_id: null,
+      completion_percent_lte: 99,
+    })
+  })
+
+  it('omits completion_percent_lte when onlyIncomplete is false', () => {
+    const f = useTaskFilters(refs)
+    expect(f.toApiParams()).not.toHaveProperty('completion_percent_lte')
+  })
 })

src/components/task/TaskFilters.vue

@@ -27,6 +27,7 @@ const emit = defineEmits([
   'update:subject-id',
   'update:term-id',
   'update:story-id',
+  'update:only-incomplete',
 ])
 
 const { t } = useI18n() // available as $t in template; used here for consistency.
@@ -114,6 +115,22 @@ const { t } = useI18n() // available as $t in template; used here for consistenc
             />
           </v-col>
 
+          <v-col cols="12">
+            <v-checkbox
+              :model-value="filters.onlyIncomplete"
+              :label="t('task.filters.onlyIncomplete')"
+              density="compact"
+              hide-details
+              color="primary"
+              @update:model-value="
+                (v) => {
+                  emit('update:only-incomplete', v)
+                  emit('apply')
+                }
+              "
+            />
+          </v-col>
+
           <v-col cols="12">
             <v-btn
               color="primary"

src/composables/useTaskFilters.js

@@ -25,6 +25,8 @@ export function useTaskFilters({ students, subjects, terms, stories }) {
     subjectId: null,
     termId: null,
     storyId: null,
+    // 只看未完成：completion_percent < 100%（覆盖 not_started + in_progress）
+    onlyIncomplete: false,
   })
 
   // 横屏（width > height）时默认收起 filter panel，避免 304px 高的 panel 把
@@ -79,16 +81,22 @@ export function useTaskFilters({ students, subjects, terms, stories }) {
       subjectId: null,
       termId: null,
       storyId: null,
+      onlyIncomplete: false,
     }
   }
 
   function toApiParams() {
-    return {
+    const params = {
       student_id: filters.value.studentId,
       subject_id: filters.value.subjectId,
       term_id: filters.value.termId,
       story_id: filters.value.storyId,
     }
+    // 只看未完成：completion_percent < 100%（兼容后端 status 枚举推导规则）
+    if (filters.value.onlyIncomplete) {
+      params.completion_percent_lte = 99
+    }
+    return params
   }
 
   // Cascade: 学生变了 → 重置学期和系列任务。

src/locales/en/modules/task.js

@@ -66,6 +66,7 @@ export default {
     expand: 'Expand Filter Panel',
     collapse: 'Collapse Filter Panel',
     expandToReselect: 'Click to Expand and Reselect',
+    onlyIncomplete: 'Only incomplete',
   },
   edit: {
     title: 'Edit Task',

src/locales/zh-CN/modules/task.js

@@ -66,6 +66,7 @@ export default {
     expand: '展开筛选面板',
     collapse: '收起筛选面板',
     expandToReselect: '点击展开重新选择',
+    onlyIncomplete: '只看未完成',
   },
   edit: {
     title: '编辑作业',

src/views/TaskView.vue

@@ -90,12 +90,7 @@ async function fetchTasks(filterParams = null) {
   isLoading.value = true
   clearError()
   try {
-    const params = filterParams || {
-      student_id: filterPanel.filters.value.studentId,
-      subject_id: filterPanel.filters.value.subjectId,
-      term_id: filterPanel.filters.value.termId,
-      story_id: filterPanel.filters.value.storyId,
-    }
+    const params = filterParams || filterPanel.toApiParams()
     const response = await getTasks(params)
     tasks.value = Array.isArray(response) ? response : []
   } catch (e) {
@@ -134,6 +129,9 @@ function onUpdateTermId(value) {
 function onUpdateStoryId(value) {
   filterPanel.filters.value.storyId = value
 }
+function onUpdateOnlyIncomplete(value) {
+  filterPanel.filters.value.onlyIncomplete = value
+}
 
 // ─── Edit dialog open / close ───────────────────────────────────────
 function openEditForTask(taskId) {
@@ -255,6 +253,7 @@ onUnmounted(() => {
         @update:subject-id="onUpdateSubjectId"
         @update:term-id="onUpdateTermId"
         @update:story-id="onUpdateStoryId"
+        @update:only-incomplete="onUpdateOnlyIncomplete"
       />
 
       <TaskCalendar