feat: saved searches

Lets users name and pin a search query from the SearchResults page;
saved searches persist to localStorage and show as quick links in a new
sidebar section, similar to Favorites. Clicking re-runs the query.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/pages/SearchResults.jsx

@@ -5,6 +5,7 @@ import EmailRow from '../components/EmailRow.jsx';
 import BulkToolbar from '../components/BulkToolbar.jsx';
 import useSelection from '../hooks/useSelection.js';
 import useListKeyboardNav from '../hooks/useListKeyboardNav.js';
+import useSavedSearches from '../hooks/useSavedSearches.js';
 
 const PAGE_SIZE = 50;
 
@@ -21,6 +22,13 @@ export default function SearchResults() {
   const [error, setError] = useState(null);
   const { selected, toggle, clear, removeIds, selectedIds } = useSelection();
   const focusedId = useListKeyboardNav(emails, (id) => setEmails((prev) => prev.filter((x) => x.id !== id)));
+  const { searches: savedSearches, add: addSavedSearch } = useSavedSearches();
+  const isSaved = savedSearches.some((s) => s.query === q);
+
+  const handleSave = () => {
+    const label = window.prompt('Name this saved search:', q);
+    if (label && label.trim()) addSavedSearch(label.trim(), q);
+  };
 
   useEffect(() => {
     setEmails([]);
@@ -63,11 +71,16 @@ export default function SearchResults() {
 
   return (
     <div className="folder-view">
-      <div className="folder-view-head">
+      <div className="folder-view-head saved-search-row">
         <h2 className="folder-view-title">🔍 "{q}"</h2>
         {totalCount !== null && (
           <span className="folder-view-count">{totalCount.toLocaleString()} result{totalCount !== 1 ? 's' : ''}</span>
         )}
+        {q.trim() && (
+          <button className="saved-search-save-btn" onClick={handleSave} disabled={isSaved}>
+            {isSaved ? '★ Saved' : '☆ Save search'}
+          </button>
+        )}
       </div>
 
       {!q.trim() && <div className="fv-empty">Enter a search query above.</div>}