fix: restore Expand/Minimize button in AI panel + dynamic width, note thumbnail SVG placeholder with emoji/letter

memento-note/components/notes-editorial-view.tsx

@@ -116,6 +116,63 @@ function EditorialNoteMenu({ note, onOpen, onOpenHistory }: {
   )
 }
 
+/** Deterministic hue from a string — consistent per note */
+function stringToHue(s: string): number {
+  let h = 0
+  for (let i = 0; i < s.length; i++) h = (h * 31 + s.charCodeAt(i)) & 0xffff
+  return h % 360
+}
+
+/** SVG thumbnail for notes without an image */
+function NoteThumbnailPlaceholder({ title, noteId }: { title: string; noteId: string }) {
+  // Try to extract the first emoji from the title
+  const emojiMatch = title.match(/\p{Emoji_Presentation}|\p{Emoji}\uFE0F/u)
+  const emoji = emojiMatch?.[0]
+  const letter = title.replace(/\p{Emoji_Presentation}|\p{Emoji}\uFE0F/gu, '').trim()[0]?.toUpperCase() || '?'
+  const hue = stringToHue(noteId)
+
+  return (
+    <div
+      className="h-full w-full flex items-center justify-center relative overflow-hidden"
+      style={{ background: `linear-gradient(145deg, hsl(${hue} 25% 94%) 0%, hsl(${hue} 18% 87%) 100%)` }}
+    >
+      {/* Decorative concentric circles */}
+      <svg
+        className="absolute inset-0 w-full h-full"
+        viewBox="0 0 224 168"
+        fill="none"
+        aria-hidden
+        style={{ color: `hsl(${hue} 30% 60%)` }}
+      >
+        <circle cx="112" cy="84" r="90" stroke="currentColor" strokeWidth="0.6" opacity="0.25" />
+        <circle cx="112" cy="84" r="64" stroke="currentColor" strokeWidth="0.6" opacity="0.2" />
+        <circle cx="112" cy="84" r="38" stroke="currentColor" strokeWidth="0.6" opacity="0.15" />
+        <line x1="22" y1="84" x2="202" y2="84" stroke="currentColor" strokeWidth="0.4" opacity="0.15" />
+        <line x1="112" y1="4" x2="112" y2="164" stroke="currentColor" strokeWidth="0.4" opacity="0.15" />
+      </svg>
+      {emoji ? (
+        <span
+          className="relative text-5xl leading-none select-none"
+          style={{ filter: `drop-shadow(0 2px 8px hsl(${hue} 40% 40% / 0.2))` }}
+        >
+          {emoji}
+        </span>
+      ) : (
+        <span
+          className="relative font-memento-serif font-bold select-none leading-none"
+          style={{
+            fontSize: '4.5rem',
+            color: `hsl(${hue} 35% 35%)`,
+            opacity: 0.35,
+          }}
+        >
+          {letter}
+        </span>
+      )}
+    </div>
+  )
+}
+
 export function NotesEditorialView({
   notes,
   onOpen,
@@ -166,7 +223,7 @@ export function NotesEditorialView({
                       className="w-full h-full object-cover mix-blend-multiply opacity-80 grayscale contrast-125 hover:grayscale-0 hover:opacity-100 transition-all duration-500"
                     />
                   ) : (
-                    <div className="h-full w-full bg-gradient-to-br from-muted/40 to-muted/10" aria-hidden />
+                    <NoteThumbnailPlaceholder title={title} noteId={note.id} />
                   )}
                 </div>
                 <div className="space-y-3 flex-1">