fix: leave task-list deadlines empty by default

frontend/src/App.vue

@@ -91,7 +91,7 @@ function openTaskCompose() {
   const inboxId = lists.value.find((item) => item.is_inbox)?.id || activeList.value
   composeTitle.value = ''
   composeListId.value = activeView.value === 'tasks' && activeList.value ? activeList.value : inboxId
-  composeDueAt.value = defaultTaskDueAt()
+  composeDueAt.value = activeView.value === 'today' ? defaultTaskDueAt() : ''
   composeHasTime.value = false
   composeTime.value = '12:00'
   composePriority.value = 0

frontend/src/style.test.ts

@@ -270,8 +270,8 @@ describe('settings data tools', () => {
 })
 
 describe('unified floating add interaction', () => {
-  it('defaults every new-task composer to today', () => {
-    expect(app).toContain('composeDueAt.value = defaultTaskDueAt()')
+  it('leaves task-list deadlines empty and keeps Today tasks due today', () => {
+    expect(app).toContain("composeDueAt.value = activeView.value === 'today' ? defaultTaskDueAt() : ''")
     expect(app).toContain('v-model="composeDueAt" type="date"')
     expect(app).not.toContain('class="time-toggle"')
     expect(app).not.toContain('v-model="composeHasTime" type="checkbox"')