feat: Remove iOS platform components to transition to Android-only application

[stanvx]

Summary

This PR completes the iOS decommissioning work to transition Notely Capture from a Kotlin Multiplatform (Android + iOS) application to an Android-only application, as outlined in task-053.

Changes Made

Core iOS Platform Removal

• ✅ Removed entire iosApp/ directory (173 files, ~56MB including Whisper.xcframework)
• ✅ Updated build configurations:
  • shared/build.gradle.kts: Removed iOS targets (iosX64, iosArm64, iosSimulatorArm64)
  • core/audio/build.gradle.kts: Removed iOS framework configurations
  • Removed iOS C interop configurations for Whisper framework
• ✅ Preserved expect/actual declarations with Android implementations intact

Documentation & Configuration Updates

• ✅ Updated .gitattributes: Removed obsolete iOS merge rules for upstream sync compatibility
• ✅ Updated README.md: Changed from "cross-platform" to "Android note-taking application"
• ✅ Updated CLAUDE.md: Removed iOS build commands, development sections, and source set references
• ✅ Updated Makefile: Platform description now reflects Android-only status

Code Cleanup & Simplification

• ✅ Simplified onboarding system:
  • Removed iOS/Android platform conditionals from OnboardingWalkthrough.kt
  • Simplified OnboardingPage data class (removed iOSResources field)
  • Updated ModelSetupPage.kt to use Android-only resource selection
• ✅ Resource cleanup: Removed 8 unused iOS onboarding images (.webp files)
• ✅ Maintained functionality: All Android features working correctly

Testing & Validation

• ✅ Android build successful: Project compiles and runs properly on Android
• ✅ Upstream sync tested: ./upstream-sync.sh functionality verified and working
• ✅ Code quality confirmed: All linting checks pass (ktlintCheck)
• ✅ No regressions detected: Core functionality remains intact
• ✅ Architecture preserved: Clean architecture layers maintained

Impact Assessment

Positive Impact

• Reduced complexity: Simplified build system and development workflow
• Smaller codebase: Removed ~56MB of iOS-specific files and dependencies
• Android focus: Enables more focused Android optimizations
• Maintained compatibility: Upstream sync functionality preserved

Breaking Changes

• iOS support removed: Application no longer supports iOS platform
• Build targets: iOS build targets no longer available

Related Tasks

• Resolves task-053: Remove iOS platform components to transition to Android-only application
• Implements doc-002: iOS Component Removal Audit recommendations

Deployment Notes

• This change affects the build system but does not impact existing Android users
• No migration required for Android installations
• Release builds will be smaller due to removed iOS components

Future Considerations

• Consider addressing the 18 security vulnerabilities detected by GitHub (separate task)
• Potential for additional Android-specific optimizations now that iOS constraints are removed

[claude]

Claude finished @stanvx's task —— View job

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Kotlin Multiplatform PR Review ✅

Reviewed this major architectural transition from Kotlin Multiplatform to Android-only application.

Review Checklist

• Analyze build configuration changes and target removal
• Review code simplifications in onboarding system
• Check for remaining iOS references or dead code
• Verify Clean Architecture boundaries are maintained
• Review Compose UI patterns and performance considerations
• Examine dependency injection and expect/actual patterns
• Check for potential security issues and bugs
• Assess documentation accuracy and completeness

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✅ Excellent work! This PR successfully transitions to Android-only while maintaining clean architecture.

🎯 Key Strengths

Build Configuration

• ✅ Clean removal of iOS targets from shared/build.gradle.kts and core/audio/build.gradle.kts
• ✅ Preserved -Xexpected-actual-classes compiler flag for remaining platform abstractions
• ✅ Maintained proper Android target configuration with JVM 17

Expect/Actual Pattern Usage

• ✅ Well-structured abstractions: Platform.kt, StatusBarManager.kt, AudioRecorder.kt
• ✅ Clean Android implementations: All expect declarations have proper actual implementations
• ✅ No orphaned expectations: No iOS-specific expect declarations left behind

Code Quality & Architecture

• ✅ Clean Architecture preserved: UI → Presentation → Domain → Data layers intact
• ✅ Dependency injection properly maintained: Koin modules work correctly (audioModule.android.kt)
• ✅ Onboarding simplification excellent: Removed iOS/Android conditionals while preserving tablet support
• ✅ Resource management: Smart OnboardingResource sealed class pattern for platform-specific drawables

Compose UI & Performance

• ✅ Efficient resource selection: OnboardingResource.forPlatform() pattern eliminates runtime checks
• ✅ Proper state management: collectAsState() and LaunchedEffect usage is correct
• ✅ Animation performance: Page indicators use animateDpAsState and animateColorAsState properly

Security & Validation

• ✅ Comprehensive security testing: SecurityTests.kt covers XSS, path traversal, input validation
• ✅ OWASP HTML Sanitizer: Properly integrated for rich text security
• ✅ Input validation: Audio file validation, path sanitization, filename validation

🔍 Minor Observations

Documentation Cleanup Needed

• ⚠️ CLAUDE.md:176,197,210,283,308,312,385 still contain iOS references
• 💡 Recommendation: Update these to reflect Android-only status

Code Organization

• ✅ OnboardingWalkthrough.kt:24 still imports getPlatform() but usage seems minimal
• ✅ Platform state management is clean and well-structured

Performance Considerations

• ✅ Audio processing: Amplitude flow pattern is well-designed for real-time audio
• ✅ Memory management: Proper lifecycle handling in ViewModels
• ✅ Resource loading: Efficient image resource selection without platform checks

🚀 Testing & Quality Assurance

Excellent Test Coverage

• ✅ Security tests comprehensive: XSS prevention, path traversal, input validation
• ✅ Audio validation: File extension validation, path sanitization
• ✅ HTML sanitization: Proper OWASP integration testing

Coroutines & StateFlow

• ✅ Proper scope usage: viewModelScope and rememberCoroutineScope() correctly used
• ✅ Flow patterns: amplitudeFlow and state collection patterns are idiomatic
• ✅ Effect handling: LaunchedEffect usage in ModelSetupPage.kt is correct

🎯 Summary

This is a high-quality PR that successfully removes iOS platform components while:

• Maintaining clean architecture boundaries
• Preserving all Android functionality
• Implementing proper security measures
• Following Kotlin Multiplatform best practices
• Demonstrating excellent Compose UI patterns

The only minor issue is some outdated iOS references in documentation files, which should be updated in a follow-up commit.

Recommendation: ✅ Ready to merge after documentation cleanup.

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