Extend search to match tool input content, not just message body

The search index (app.tsx) and the per-message match check
(SessionViewer.tsx) now also search msg.toolInput when present.
This means searching for a file path, command, or argument that
appears in a tool call's input will correctly highlight and
navigate to that message, rather than dimming it as a non-match.

Both locations use the same compound condition so the match index
and the visual dimming/focus logic stay in sync.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/client/components/SessionViewer.tsx

@@ -197,9 +197,11 @@ export function SessionViewer({
             );
           }
           const msg = item.message;
+          const lq = searchQuery ? searchQuery.toLowerCase() : "";
           const isMatch =
             searchQuery &&
-            msg.content.toLowerCase().includes(searchQuery.toLowerCase());
+            (msg.content.toLowerCase().includes(lq) ||
+              (msg.toolInput && msg.toolInput.toLowerCase().includes(lq)));
           const isDimmed = searchQuery && !isMatch;
           const isFocused = item.messageIndex === focusedIndex;
           return (