fix(todo): the + is not dragged over a day's hours, in Today's Calendar and Upcoming's 3-day

There a tap, a click or a stretch dragged says when (the developer's
review, 10 Nov 2026); Upcoming's agenda and the lists keep dragging it.

Whats-New: In Calendar and 3-day, the + button no longer drags; tap the hours instead.
Whats-New-De: In Kalender und 3 Tage lässt sich der +-Knopf nicht mehr ziehen; tippe stattdessen auf die Stunden.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tizian 「ティツィアーン」 <raisondetredev@pm.me>

apps/todo/halkyon_todo_flutter/lib/src/feature/task/widget/task_drag.dart

@@ -437,9 +437,14 @@ class const NewTaskDropArea({
 
 /// The button adding a task, above the navigation bar (ADR 0033, D2); it
 /// can be dragged onto the list to add the task there (D16), its place
-/// meanwhile a larger × where dropping it gives up.
-class const AddTaskButton({required final VoidCallback onPressed, super.key})
-    extends StatelessWidget {
+/// meanwhile a larger × where dropping it gives up. Not [draggable] over
+/// the hours of a day, where a tap or a stretch dragged says when instead
+/// (the developer's review, 10 Nov 2026).
+class const AddTaskButton({
+  required final VoidCallback onPressed,
+  final bool draggable = true,
+  super.key,
+}) extends StatelessWidget {
   /// The key of the × left in the button's place while it is dragged.
   static const cancelKey = ValueKey('add-task-cancel');
 
@@ -447,6 +452,16 @@ class const AddTaskButton({required final VoidCallback onPressed, super.key})
   Widget build(BuildContext context) {
     final l10n = AppLocalizations.of(context);
     final scheme = Theme.of(context).colorScheme;
+    final button = FloatingActionButton(
+      // Every tab keeps its own, alive beside the others: no hero flies.
+      heroTag: null,
+      tooltip: l10n.taskAddTitle,
+      onPressed: onPressed,
+      child: const Icon(LucideIcons.plus),
+    );
+    if (!draggable) {
+      return button;
+    }
     return Draggable<NewTaskDrag>(
       data: const NewTaskDrag(),
       dragAnchorStrategy: pointerDragAnchorStrategy,
@@ -487,13 +502,7 @@ class const AddTaskButton({required final VoidCallback onPressed, super.key})
           ),
         ),
       ),
-      child: FloatingActionButton(
-        // Every tab keeps its own, alive beside the others: no hero flies.
-        heroTag: null,
-        tooltip: l10n.taskAddTitle,
-        onPressed: onPressed,
-        child: const Icon(LucideIcons.plus),
-      ),
+      child: button,
     );
   }
 }

apps/todo/halkyon_todo_flutter/lib/src/tabs/today_tab.dart

@@ -77,7 +77,10 @@ class _TodayTabState() extends State<TodayTab> with PlanHost<TodayTab> {
       ],
       floatingActionButton: calendar && planSheetOpen
           ? null
-          : AddTaskButton(onPressed: () => showQuickAdd(context, day: today)),
+          : AddTaskButton(
+              draggable: !calendar,
+              onPressed: () => showQuickAdd(context, day: today),
+            ),
       body: Column(
         children: [
           const KeysResetBanner(),

apps/todo/halkyon_todo_flutter/lib/src/tabs/upcoming_tab.dart

@@ -89,6 +89,7 @@ class _UpcomingTabState()
       floatingActionButton: planSheetOpen
           ? null
           : AddTaskButton(
+              draggable: upcoming.layout != UpcomingLayout.threeDay,
               onPressed: () => showQuickAdd(
                 context,
                 day: switch (_selected) {