fix: UX polish across web and native — error boundaries, query tuning, and i18n improvements

- Add `RouteError` component for route-level error boundaries (web) with "Try again" and "Dashboard" links; wire it into dashboard, explore, upcoming, people, and settings routes
- Add `await queryClient.cancelQueries()` before every optimistic update in `useTitleActions` to prevent in-flight refetches from overwriting local state
- Cap all `useInfiniteQuery` calls at `maxPages: 10` (web and native) to bound memory growth on scroll-heavy pages
- Replace `ActivityIndicator` with `Spinner` in search, person detail, and list footer components (native)
- Tune native query client defaults: add `staleTime: 60_000` and lower `gcTime` to `300_000` (was 24h)
- Darken `--color-muted-foreground` for better contrast in the native theme
- Improve error message copy in `error-messages.ts` for clarity (TMDB, import, registration errors)
- Update i18n `.po` files across all 12 locales with new strings (route error, improved error messages)

apps/native/src/app/(tabs)/(home)/upcoming.tsx

@@ -33,6 +33,7 @@ export default function UpcomingScreen() {
         }),
         initialPageParam: undefined as string | undefined,
         getNextPageParam: (lastPage) => lastPage.nextCursor ?? undefined,
+        maxPages: 10,
       }),
     );