Android v1.2.2

chore: remove agent skills and clean up project structure

- Delete .agents/skills/building-components directory and all references
- Remove .DS_Store system files
- Delete masterprompt.md and skills-lock.json
- Refactor mobile app screens: move auth and loading components to screen level
- Add poster-image component for content display
- Create design tokens module (tokens.ts) for unified styling
- Update RootApp.tsx with simplified navigation structure
- Consolidate settings and downloads screens into main navigation
- Remove deprecated premium-background and startup-animation components
- Update .gitignore to exclude system and lock files
- Streamline component hierarchy and reduce unnecessary abstractions