feat: add undo toasts for task and note deletions

- Capture deleted item before DELETE call
- Show sonner toast with Undo action button
- On Undo, POST to recreate the item with original data
- Applied to tasks-list-view, task-detail-panel, and notes page

apps/web/app/(dashboard)/notes/page.tsx

@@ -226,6 +226,7 @@ export default function NotesPage() {
     }
     ++saveVersion.current;
     setDeleting(true);
+    const deletedNote = { ...noteToDelete };
     try {
       const response = await fetch(`/api/domains/${domainId}/notes/${noteToDelete.id}`, { method: 'DELETE' });
       if (!response.ok) throw new Error('Unable to delete note.');
@@ -234,7 +235,30 @@ export default function NotesPage() {
         selected?.id === noteToDelete.id ? notes.find((note) => note.id !== noteToDelete.id) || null : selected
       );
       setNoteToDelete(null);
-      toast.success('Note deleted');
+      toast.success('Note deleted', {
+        action: {
+          label: 'Undo',
+          onClick: async () => {
+            try {
+              const res = await fetch(`/api/domains/${domainId}/notes`, {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({
+                  title: deletedNote.title,
+                  content: deletedNote.content,
+                }),
+              });
+              if (!res.ok) throw new Error();
+              const restored = await res.json();
+              setNotes((current) => [restored, ...current]);
+              setSelectedNote(restored);
+              toast.success('Note restored');
+            } catch {
+              toast.error('Unable to restore note');
+            }
+          },
+        },
+      });
     } catch (error) {
       console.error('Failed to delete note:', error);
       toast.error('Unable to delete note');

apps/web/components/tasks/task-detail-panel.tsx

@@ -148,6 +148,7 @@ export function TaskDetailPanel({
   async function handleDelete() {
     if (!task || !domainId) return;
     setDeleting(true);
+    const deletedTask = { ...task };
     try {
       const response = await fetch(`/api/domains/${domainId}/tasks/${task.id}`, {
         method: 'DELETE',
@@ -156,7 +157,34 @@ export function TaskDetailPanel({
       onUpdate();
       setDeleteOpen(false);
       onOpenChange(false);
-      toast.success('Task deleted');
+      toast.success('Task deleted', {
+        action: {
+          label: 'Undo',
+          onClick: async () => {
+            try {
+              await fetch(`/api/domains/${domainId}/tasks`, {
+                method: 'POST',
+                headers: { 'Content-Type': 'application/json' },
+                body: JSON.stringify({
+                  title: deletedTask.title,
+                  description: deletedTask.description,
+                  status: deletedTask.status,
+                  priority: deletedTask.priority,
+                  dueDate: deletedTask.dueDate,
+                  estimatedMinutes: deletedTask.estimatedMinutes,
+                  projectId: deletedTask.projectId,
+                  sectionId: deletedTask.sectionId,
+                  parentId: deletedTask.parentId,
+                }),
+              });
+              onUpdate();
+              toast.success('Task restored');
+            } catch {
+              toast.error('Unable to restore task');
+            }
+          },
+        },
+      });
     } catch (error) {
       console.error('Failed to delete task:', error);
       toast.error('Unable to delete task');

apps/web/components/tasks/tasks-list-view.tsx

@@ -284,12 +284,38 @@ export function TasksListView({
               onClick={async () => {
                 if (!deleteId || !domainId) return;
                 setDeleting(true);
+                const deletedTask = tasks.find(t => t.id === deleteId);
                 try {
                   const res = await fetch(`/api/domains/${domainId}/tasks/${deleteId}`, { method: 'DELETE' });
                   if (!res.ok) throw new Error();
-                  toast.success('Task deleted');
                   setDeleteId(null);
                   fetchTasks();
+                  toast.success('Task deleted', {
+                    action: {
+                      label: 'Undo',
+                      onClick: async () => {
+                        if (!deletedTask) return;
+                        try {
+                          await fetch(`/api/domains/${domainId}/tasks`, {
+                            method: 'POST',
+                            headers: { 'Content-Type': 'application/json' },
+                            body: JSON.stringify({
+                              title: deletedTask.title,
+                              description: deletedTask.description,
+                              status: deletedTask.status,
+                              priority: deletedTask.priority,
+                              dueDate: deletedTask.dueDate,
+                              projectId: deletedTask.projectId,
+                            }),
+                          });
+                          fetchTasks();
+                          toast.success('Task restored');
+                        } catch {
+                          toast.error('Unable to restore task');
+                        }
+                      },
+                    },
+                  });
                 } catch {
                   toast.error('Unable to delete task');
                 } finally {