fix: preserve filters on language toggle and allow language chip deselection

- LangToggle now preserves URL query params (filters) when switching
  between PT/EN, preventing filter state loss
- Language chips now toggle off when re-clicked (consistent with label
  chip behavior), instead of requiring the "All" button

Author: Felipeness

src/components/lang-toggle.tsx

@@ -11,7 +11,8 @@ export function LangToggle() {
   const nextLocale = locale === "pt" ? "en" : "pt";
 
   function handleToggle() {
-    router.replace(pathname, { locale: nextLocale });
+    const search = typeof window !== "undefined" ? window.location.search : "";
+    router.replace(pathname + search, { locale: nextLocale });
   }
 
   return (

src/features/search/components/language-chips.tsx

@@ -22,7 +22,7 @@ export function LanguageChips({ active, onChange }: LanguageChipsProps) {
           <Chip
             key={lang.value}
             active={active === lang.value}
-            onClick={() => onChange(lang.value)}
+            onClick={() => onChange(active === lang.value ? "" : lang.value)}
           >
             {lang.value === "" ? t("allLangs") : lang.label}
           </Chip>