fix: include overdue tasks in today summary

frontend/src/App.vue

@@ -377,10 +377,17 @@ async function loadTodayTaskSummary() {
       const data = await api(`/tasks?${params}`)
       return Number(data.total ?? data.items?.length ?? 0)
     }
-    const [open, completed] = await Promise.all([summaryTotal(false), summaryTotal(true)])
+    const overdueTotal = async () => {
+      const params = new URLSearchParams({ page: '1', page_size: '1' })
+      params.set('due_to', isoAtLocalDayOffset(0))
+      params.set('completed', 'false')
+      const data = await api(`/tasks?${params}`)
+      return Number(data.total ?? data.items?.length ?? 0)
+    }
+    const [open, completed, overdue] = await Promise.all([summaryTotal(false), summaryTotal(true), overdueTotal()])
     if (token !== todaySummaryLoadToken || activeView.value !== 'today') return
     todayTaskCompleted.value = completed
-    todayTaskTotal.value = open + completed
+    todayTaskTotal.value = overdue + open + completed
   } catch { /* 概览统计失败不阻断今天页 */ }
 }
 async function loadOverdueTasks() {

frontend/src/style.test.ts

@@ -164,7 +164,9 @@ describe('task and habit row decoration', () => {
     expect(app).toContain('async function loadTodayTaskSummary()')
     expect(app).toContain('const token = ++todaySummaryLoadToken')
     expect(app).toContain("params.set('completed', String(completed))")
-    expect(app).toContain('await Promise.all([summaryTotal(false), summaryTotal(true)])')
+    expect(app).toContain('const overdueTotal = async () => {')
+    expect(app).toContain('await Promise.all([summaryTotal(false), summaryTotal(true), overdueTotal()])')
+    expect(app).toContain('todayTaskTotal.value = overdue + open + completed')
     expect(app).toContain("if (activeView.value === 'today') void loadTodayTaskSummary()")
     expect(app).toContain('aria-controls="today-tasks"')
     expect(app).toContain('aria-controls="today-habits"')