fix(tv): replace season sheet with advanced request modal, not stack it

When a user has advanced-request permission, the season-select sheet
opened the advanced request modal via router.back() + push(). back() is
batched, so the push landed first and the advanced sheet stacked on top
of the season sheet, breaking focus. Add a `replace` option to
showRequestModal and use it here so the advanced modal takes the season
sheet's place in the stack.

Claude-Session: https://claude.ai/code/session_016Hhu5DruGLPhdP4LAoy1Xd

app/(auth)/tv-season-select-modal.tsx

@@ -257,14 +257,15 @@ export default function TVSeasonSelectModalPage() {
     };
 
     if (modalState.hasAdvancedRequestPermission) {
-      // Close this modal and open the advanced request modal
-      router.back();
+      // Replace this sheet with the advanced request modal so it takes our
+      // place in the stack instead of stacking on top (which breaks focus).
       showRequestModal({
         requestBody: body,
         title: modalState.title,
         id: modalState.mediaId,
         mediaType: MediaType.TV,
         onRequested: modalState.onRequested,
+        replace: true,
       });
       return;
     }