Add music theory curriculum with interactive lessons

Created by: jedmund

Overview

Implements a comprehensive music theory learning app with interactive lessons, exercises, and playable keyboard.

Key Changes

Content & Data

• Added chromatic scale music theory content module
• Updated exercise and lesson JSON references

Core Models

• Lesson, Module, Track - curriculum structure
• ContentBlock, Check, Exercise - lesson content types
• ToolType, PlayableKeyboardConfig, MultipleChoiceConfig - interactive elements
• PitchParsing - musical note parsing utilities

Views & UI

• Navigation: Home, Track, Module, Lesson screens with headers
• Cards: LessonCard, ModuleCard, TrackCard with custom styling
• Lesson Pages: Content blocks (callouts, quizzes), multiple choice, exercises
• Interactive: PlayableKeyboardView with synthesizer integration
• Tools: ToolViewFactory for dynamic tool rendering

Services & State

• AudioEngine - AudioKit-based sound synthesis and playback
• CurriculumStore - curriculum state management
• ContentLoader - JSON content loading
• SampleData - development sample curriculum data

Features

• Vertical paging through lesson content
• Split layout: reading region + interactive region
• Playable synthesizer keyboard with AudioKit
• Interactive content blocks and inline quizzes
• Progress tracking through lessons