style(workspace-notes): larger, more spacious note title

Title input bumps to 1.4rem with Fraunces serif (matches the
design language's heading treatment) and gains 0.9/1.1rem padding
on the title row for breathing room.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/components/WorkspaceNoteEditor.vue

@@ -741,7 +741,7 @@ defineExpose({ reload: loadProjectNotes });
 .btn-save:disabled { opacity: 0.4; cursor: default; }
 
 .note-title-row {
-  padding: 0.5rem 0.75rem;
+  padding: 0.9rem 1.1rem 0.5rem;
   flex-shrink: 0;
 }
 
@@ -749,12 +749,19 @@ defineExpose({ reload: loadProjectNotes });
   width: 100%;
   background: transparent;
   border: none;
-  font-size: 1rem;
+  font-size: 1.4rem;
   font-weight: 600;
+  line-height: 1.25;
   color: var(--color-text);
   padding: 0;
+  font-family: 'Fraunces', serif;
+  letter-spacing: -0.01em;
 }
 .note-title-input:focus { outline: none; }
+.note-title-input::placeholder {
+  color: var(--color-text-muted);
+  font-style: italic;
+}
 
 .tag-row {
   display: flex;