fix(gifPicker): rewire mobile-web back arrow to return to default view

On mobile web the header's arrow button called control.close(),
collapsing the dialog entirely and giving users no way to exit search
results back to the categories view. Wire it to onGoBack instead, which
already clears the search, resets to trending, and only closes the
dialog when the user is already at that default state.

Addresses PR #10261 feedback from surfdude29: no way back from the
search results screen to the default view.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/features/gifPicker/components/GifPickerHeader.tsx

@@ -12,12 +12,12 @@ import {IS_WEB} from '#/env'
 export function GifPickerHeader({
   inputRef,
   onChangeText,
-  onClose,
+  onGoBack,
   onEscape,
 }: {
   inputRef: Ref<TextInput>
   onChangeText: (text: string) => void
-  onClose: () => void
+  onGoBack: () => void
   onEscape: () => void
 }) {
   const {t: l} = useLingui()
@@ -40,8 +40,8 @@ export function GifPickerHeader({
           size="small"
           color="secondary"
           shape="round"
-          onPress={onClose}
-          label={l`Close GIF dialog`}>
+          onPress={onGoBack}
+          label={l`Go back`}>
           <ButtonIcon icon={Arrow} size="md" />
         </Button>
       )}