fix(vidstack): guard localStorage access when unavailable

[cycsmail]

Summary

• add a LocalStorage wrapper in utils/storage.ts that guards getItem/setItem/removeItem in a try/catch
• route the player's storage reads/writes (media storage, font vars/options, default-layout menu checkbox) through it

Why

Some mobile WebViews expose localStorage as null (or throw on access when storage is disabled), so the direct localStorage.getItem(...) calls throw a TypeError and crash the player on init. The wrapper returns null / no-ops in that case instead of throwing.

pnpm --filter vidstack test passes (64 tests), including a new media-storage.test.ts that stubs localStorage as null and asserts LocalMediaStorage doesn't throw. typecheck/oxfmt not run in this pass.

Fixes #1444.