remove(highlights): remove 'Show context' functionality from highlight items

src/components/HighlightItem.tsx

@@ -69,12 +69,6 @@ export const HighlightItem: React.FC<HighlightItemProps> = ({ highlight, onSelec
           </div>
         )}
         
-        {highlight.context && (
-          <details className="highlight-context">
-            <summary>Show context</summary>
-            <p className="context-text">{highlight.context}</p>
-          </details>
-        )}
         
         <div className="highlight-meta">
           <span className="highlight-time">

src/index.css

@@ -1542,31 +1542,6 @@ body {
   line-height: 1.5;
 }
 
-.highlight-context {
-  margin-top: 0.5rem;
-}
-
-.highlight-context summary {
-  cursor: pointer;
-  font-size: 0.875rem;
-  color: #888;
-  user-select: none;
-  transition: color 0.2s ease;
-}
-
-.highlight-context summary:hover {
-  color: #aaa;
-}
-
-.context-text {
-  margin: 0.5rem 0 0 0;
-  padding: 0.75rem;
-  background: #252525;
-  border-radius: 6px;
-  font-size: 0.875rem;
-  color: #aaa;
-  line-height: 1.5;
-}
 
 .highlight-meta {
   display: flex;