Revamp Flow UI across mobile, media, and TV

[PastaHimself]

What changed

Small ui revamp

• Updated the main app screens, media players, Shorts controls, onboarding, settings, and TV interface.
• Added shared UI components for spacing, shapes, icons, motion, screen states, and navigation.
• Added navigation that adapts between a bottom bar on phones and a side rail on wider screens.
• Improved accessibility with clearer labels, selection states, and 48 dp minimum touch targets.
• Added tests for the updated UI components and screens.