feat(notes): notes get their own list, a day log and an Enter chain

The editor was reachable from one button that only appeared in My Day,
which is how it got forgotten. It is now a permanent sidebar entry next
to My Day and Planned, and it fills the tasks island rather than the
details pane, because a note list is content.

Inside, the date picker is gone: today sits at the top with the capture
box, older days follow as dated groups. Enter in a note saves it and
opens the next one, Shift+Enter breaks the line so notes can be several,
Backspace on an empty note deletes it and steps back up. Deleting also
has a visible hover button instead of only "clear the text and hope".
Agent-written notes carry a marker.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/ClaudeDo.Ui/Services/Interfaces/INotesApi.cs

@@ -5,6 +5,8 @@ namespace ClaudeDo.Ui.Services.Interfaces;
 public interface INotesApi
 {
     Task<List<DailyNoteDto>> ListAsync(DateOnly day);
+    /// <summary>Both ends inclusive — today plus its history in one call.</summary>
+    Task<List<DailyNoteDto>> ListBetweenAsync(DateOnly start, DateOnly end);
     Task<DailyNoteDto?> AddAsync(DateOnly day, string text);
     Task UpdateAsync(string id, string text);
     Task DeleteAsync(string id);