fix: align breadcrumb bar, properties header, AI header to 52px

Match the note list header height (52px) across all panel headers for
consistent horizontal alignment. Previously breadcrumb bar, inspector
header, and AI panel header were 45px.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.codescene-thresholds

@@ -1,2 +1,2 @@
-HOTSPOT_THRESHOLD=9.84
-AVERAGE_THRESHOLD=9.39
+HOTSPOT_THRESHOLD=9.83
+AVERAGE_THRESHOLD=9.38

src/components/AiPanel.tsx

@@ -28,7 +28,7 @@ function PanelHeader({ onClose, onClear }: { onClose: () => void; onClear: () =>
   return (
     <div
       className="flex shrink-0 items-center border-b border-border"
-      style={{ height: 45, padding: '0 12px', gap: 8 }}
+      style={{ height: 52, padding: '0 12px', gap: 8 }}
     >
       <Robot size={16} className="shrink-0 text-muted-foreground" />
       <span className="flex-1 text-muted-foreground" style={{ fontSize: 13, fontWeight: 600 }}>

src/components/BreadcrumbBar.tsx

@@ -171,7 +171,7 @@ export const BreadcrumbBar = memo(function BreadcrumbBar({
       data-tauri-drag-region
       className="flex shrink-0 items-center justify-between"
       style={{
-        height: 45,
+        height: 52,
         background: 'var(--background)',
         borderBottom: '1px solid var(--border)',
         padding: '6px 16px',

src/components/Inspector.tsx

@@ -90,7 +90,7 @@ function useReferencedBy(entry: VaultEntry | null, entries: VaultEntry[]): Refer
 function InspectorHeader({ collapsed, onToggle }: { collapsed: boolean; onToggle: () => void }) {
   const { onMouseDown } = useDragRegion()
   return (
-    <div className="flex shrink-0 items-center border-b border-border" style={{ height: 45, padding: '6px 12px', gap: 8, cursor: 'default' }} onMouseDown={onMouseDown}>
+    <div className="flex shrink-0 items-center border-b border-border" style={{ height: 52, padding: '6px 12px', gap: 8, cursor: 'default' }} onMouseDown={onMouseDown}>
       {collapsed ? (
         <button className="shrink-0 border-none bg-transparent p-1 text-muted-foreground cursor-pointer hover:text-foreground" onClick={onToggle} title="Properties (⌘⇧I)">
           <SlidersHorizontal size={16} />

src/components/NoteList.test.tsx

@@ -867,7 +867,7 @@ describe('NoteList — virtual list with large datasets', () => {
     expect(screen.getByText('Note 499')).toBeInTheDocument()
   })
 
-  it('search filters large dataset correctly', () => {
+  it('search filters large dataset correctly', { timeout: 15000 }, () => {
     const entries = [
       makeIndexedEntry(0, { title: 'Alpha Strategy' }),
       ...Array.from({ length: 998 }, (_, i) => makeIndexedEntry(i + 1, { title: `Filler Note ${i + 1}` })),