Fix search results flickering between old and new queries

When navigating from the sidebar search, the URL param (?q=) updates
immediately but the local searchQuery state lagged one render cycle
behind (synced via useEffect). During that gap, the old query's
results would briefly flash before being cleared.

Fix: derive an effectiveQuery directly from the URL search params and
use it for all data fetching and conditional rendering. The local
searchQuery state is kept only as the controlled input value.

Closes #72

src/pages/SearchPage.tsx

@@ -96,6 +96,10 @@ export function SearchPage() {
 
   // Local input state for the search field (avoids trimming while typing)
   const [searchQuery, setSearchQuery] = useState(searchParams.get('q') ?? '');
+
+  // The effective query used for data fetching — derived directly from URL
+  // params so it is never one render behind when navigating from the sidebar.
+  const effectiveQuery = searchParams.get('q') ?? '';
   const [filtersOpen, setFiltersOpen] = useState(false);
 
   // ── Filter state — all derived from URL params ──────────────────────────
@@ -271,7 +275,7 @@ export function SearchPage() {
     const parts: string[] = bridged.length > 0
       ? bridged.map(p => `protocol:${p}`)
       : ['protocol:nostr'];
-    if (searchQuery.trim()) parts.push(searchQuery.trim());
+    if (effectiveQuery.trim()) parts.push(effectiveQuery.trim());
     if (language !== 'global') parts.push(`language:${language}`);
     const isDedicatedKindQuery = !kindsOverride && (mediaType === 'vines' || mediaType === 'images' || mediaType === 'videos');
     if (!isDedicatedKindQuery && !hasKindMediaConflict) {
@@ -282,7 +286,7 @@ export function SearchPage() {
     if (sort === 'hot') parts.push('sort:hot');
     else if (sort === 'trending') parts.push('sort:trending');
     return parts.join(' ');
-  }, [searchQuery, language, mediaType, protocols, kindsOverride, hasKindMediaConflict, sort]);
+  }, [effectiveQuery, language, mediaType, protocols, kindsOverride, hasKindMediaConflict, sort]);
 
   // Active filter labels for the summary / empty state hints
   const activeFilterLabels = useMemo(() => {
@@ -330,11 +334,11 @@ export function SearchPage() {
   // Build a standard NIP-01 TabFilter from the current search state
   const currentFilter = useMemo<TabFilter>(() => {
     const filter: TabFilter = {};
-    if (searchQuery.trim()) filter.search = searchQuery.trim();
+    if (effectiveQuery.trim()) filter.search = effectiveQuery.trim();
     if (kindsOverride && kindsOverride.length > 0) filter.kinds = kindsOverride;
     if (authorScope === 'people' && authorPubkeys.length > 0) filter.authors = authorPubkeys;
     return filter;
-  }, [searchQuery, kindsOverride, authorScope, authorPubkeys]);
+  }, [effectiveQuery, kindsOverride, authorScope, authorPubkeys]);
 
   const alreadySaved = savedFeeds.some(
     (f) => JSON.stringify(f.filter) === JSON.stringify(currentFilter),
@@ -372,7 +376,7 @@ export function SearchPage() {
       ? authorPubkeys
       : undefined;
 
-  const { posts, isLoading: postsLoading } = useStreamPosts(searchQuery, {
+  const { posts, isLoading: postsLoading } = useStreamPosts(effectiveQuery, {
     includeReplies,
     mediaType,
     language,
@@ -381,7 +385,7 @@ export function SearchPage() {
     authorPubkeys: streamAuthorPubkeys,
     sort,
   });
-  const { data: profiles, isLoading: profilesLoading, followedPubkeys } = useSearchProfiles(activeTab === 'accounts' ? searchQuery : '');
+  const { data: profiles, isLoading: profilesLoading, followedPubkeys } = useSearchProfiles(activeTab === 'accounts' ? effectiveQuery : '');
 
   return (
     <main className="">
@@ -700,7 +704,7 @@ export function SearchPage() {
             )}
 
             {/* NIP-50 search query debug block */}
-            {searchQuery.trim() && (
+            {effectiveQuery.trim() && (
               <TooltipProvider>
                 <Tooltip>
                   <TooltipTrigger asChild>
@@ -732,7 +736,7 @@ export function SearchPage() {
                 <NoteCard key={event.id} event={event} />
               ))}
             </div>
-          ) : searchQuery.trim() ? (
+          ) : effectiveQuery.trim() ? (
             <EmptyState
               message="No posts found matching your search."
               activeFilters={activeFilterLabels}
@@ -762,7 +766,7 @@ export function SearchPage() {
           </div>
 
           <div>
-            {searchQuery.trim() ? (
+            {effectiveQuery.trim() ? (
               profilesLoading ? (
                 <div className="divide-y divide-border">
                   {Array.from({ length: 5 }).map((_, i) => (