Fix: Allow search suggestions with empty query for popular results

Changes:
- Comment out early return when query is empty
- Allow recoSearch to be called with empty/trimmed query
- Backend returns popular cities/regions when query is empty
- Enables showing suggestions immediately on focus (UX improvement)

Backend test confirms it works:
$ curl "http://localhost:8081/api/suggestions?q="
Returns: 6 popular suggestions (Montreal, Quebec City, Toronto, etc.)

$ curl "http://localhost:8081/api/suggestions?q=to"
Returns: Toronto, Seattle, Boston

Now users will see suggestions as they type + popular items on focus

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/components/Search/SmartSearchBar.jsx

@@ -85,12 +85,14 @@ export default function SmartSearchBar({
     setErr("");
 
     if (abortRef.current) abortRef.current.abort();
-    if (!query) {
-      setItems([]);
-      setLoading(false);
-      setActive(-1);
-      return;
-    }
+
+    // Allow empty query to get popular suggestions
+    // if (!query) {
+    //   setItems([]);
+    //   setLoading(false);
+    //   setActive(-1);
+    //   return;
+    // }
 
     const ctrl = new AbortController();
     abortRef.current = ctrl;