Summary

This PR introduces the Typelets mobile app (React Native with Expo) and includes comprehensive refactoring to
establish a clean, modular architecture following single responsibility principles.

Features

• 🔐 End-to-end encryption with master password protection (AES-GCM + PBKDF2)
• 📱 Cross-platform support (iOS and Android)
• 📁 Folder organization with nested folder support
• ⭐ Starred notes and trash management
• 🎨 Light and dark theme support
• 📝 Rich text editing with TipTap
• 🔄 Real-time sync with backend API

Architectural Improvements

API Service Refactoring

• Split 432-line api.ts into 9 focused modules
• Separated concerns: notes, folders, encryption, client, types
• Centralized error handling and pagination utilities
• Result: Clean, testable, maintainable API layer

Encryption Service Refactoring

• Split 674-line encryption.ts into 13 focused modules
• Organized into: core (AES, PBKDF2, crypto), storage (cache, secureStorage), masterPassword
• AES-GCM encryption with 250,000 PBKDF2 iterations
• LRU cache for decrypted notes (15-minute TTL)
• Result: Well-structured encryption layer with clear separation of concerns

MasterPasswordDialog Refactoring

• Split 578-line component into 6 focused modules
• Custom hooks: useKeyboardHandler, usePasswordValidation
• Separated components: MasterPasswordForm, LoadingView
• Isolated styles and business logic
• Result: Maintainable, testable password UI components

Tech Stack

• Framework: React Native with Expo 54
• Routing: Expo Router (file-based)
• Authentication: Clerk
• Encryption: AES-GCM with PBKDF2
• Storage: Expo SecureStore

Testing

• ✅ Lint: 0 errors, 21 warnings (pre-existing)
• ✅ All imports maintain backward compatibility
• ✅ Zero breaking changes across refactorings
• ✅ Manual testing on Android (preview build)

Version Management

• Automatic version bumping via semantic-release
• Syncs package.json, app.json, iOS buildNumber, Android versionCode
• Triggered by feat(mobile):, fix(mobile):, refactor(mobile): commits

Documentation

• Comprehensive README with architecture overview
• API and encryption usage examples
• Development and build instructions
• Security and contributing guidelines

Commits

• feat(mobile): initial React Native mobile app with encryption
• feat: add mobile app v1
• refactor(mobile): modularize API service into smaller, maintainable modules
• refactor(mobile): modularize encryption service into focused, maintainable modules
• chore(mobile): remove unused auth context and state files
• refactor(mobile): break down MasterPasswordDialog into modular components
• refactor(mobile): fix lint errors
• refactor(mobile): remove verbose debug logging from password and encryption modules
• docs(mobile): add comprehensive README documentation

Breaking Changes

None - all refactorings maintain backward compatibility.