Enhance Overworld Editor with v3 features and unified settings management

- Implemented full support for ZSCustomOverworld v3, including complex transition calculations and interactive overlays.
- Introduced a new unified settings table in OverworldEditorManager for streamlined management of toolsets and properties.
- Enhanced scratch space functionality with selection transfer capabilities between overworld and scratch slots.
- Removed the outdated ZEML system in favor of a pure ImGui layout for improved performance and maintainability.
- Updated changelog to reflect significant new features and improvements in the Overworld Editor.

docs/C1-changelog.md

@@ -6,7 +6,9 @@
 - **Complete Tile16 Editor Overhaul**: Professional-grade tile editing with modern UI and advanced capabilities
 - **Advanced Palette Management**: Full access to all SNES palette groups with configurable normalization
 - **Comprehensive Undo/Redo System**: 50-state history with intelligent time-based throttling
-- **Scratch Space for Overworld**: Not yet compatible with ZScream
+- **ZSCustomOverworld v3 Full Support**: Complete implementation of ZScream Save.cs functionality with complex transition calculations
+- **ZEML System Removal**: Converted overworld editor from markup to pure ImGui for better performance and maintainability
+- **OverworldEditorManager**: New management system to handle complex v3 overworld features
 
 ### Tile16 Editor Enhancements
 - **Modern UI Layout**: Fully resizable 3-column interface (Tile8 Source, Editor, Preview & Controls)
@@ -15,17 +17,30 @@
 - **Professional Workflow**: Copy/paste, 4-slot scratch space, live preview with auto-commit
 - **Pixel Normalization Settings**: Configurable pixel value masks (0x01-0xFF) for handling corrupted graphics sheets
 
+### ZSCustomOverworld v3 Implementation
+- **SaveLargeMapsExpanded()**: Complex neighbor-aware transition calculations for all area sizes (Small, Large, Wide, Tall)
+- **Interactive Overlay System**: Full `SaveMapOverlays()` with ASM code generation for revealing holes and changing map elements
+- **SaveCustomOverworldASM()**: Complete custom overworld ASM application with feature toggles and data tables
+- **Expanded Memory Support**: Automatic detection and use of v3 expanded memory locations (0x140xxx)
+- **Area-Specific Features**: Background colors, main palettes, mosaic transitions, GFX groups, subscreen overlays, animated tiles
+- **Transition Logic**: Sophisticated camera transition calculations based on neighboring area types and quadrants
+- **Version Compatibility**: Maintains vanilla/v2 compatibility while adding full v3+ feature support
+
 ### Technical Improvements
 - **SNES Data Accuracy**: Proper 4-bit palette index handling with configurable normalization
 - **Bitmap Pipeline Fixes**: Corrected tile16 extraction using `GetTilemapData()` with manual fallback
 - **Real-time Updates**: Immediate visual feedback for all editing operations
 - **Memory Safety**: Enhanced bounds checking and error handling throughout
+- **ASM Version Detection**: Automatic detection of custom overworld ASM version for feature availability
+- **Conditional Save Logic**: Different save paths for vanilla, v2, and v3+ ROMs
 
 ### User Interface
 - **Keyboard Shortcuts**: Comprehensive shortcuts for all operations (H/V/R for transforms, Q/E for palette cycling, 1-8 for direct palette selection)
 - **Visual Feedback**: Hover preview restoration, current palette highlighting, texture status indicators
 - **Compact Controls**: Streamlined property panel with essential tools easily accessible
 - **Settings Dialog**: Advanced palette normalization controls with real-time application
+- **Pure ImGui Layout**: Removed ZEML markup system in favor of native ImGui tabs and tables for better performance
+- **v3 Settings Panel**: Dedicated UI for ZSCustomOverworld v3 features with ASM version detection and feature toggles
 
 ### Bug Fixes
 - **Tile16 Bitmap Display**: Fixed blank/white tile issue caused by unnormalized pixel values
@@ -34,8 +49,15 @@
 - **Palette Corruption**: Fixed high-bit contamination in graphics sheets
 - **UI Layout**: Proper column sizing and resizing behavior
 - **Linux CI/CD Build**: Fixed undefined reference errors for `ShowSaveFileDialog` method
+- **ZSCustomOverworld v3**: Fixed complex area transition calculations and neighbor-aware tilemap adjustments
+- **ZEML Performance**: Eliminated markup parsing overhead by converting to native ImGui components
 
-- Minor bug fixes for color themes and ZSCustomOverworld v3 item loading.
+### ZScream Compatibility Improvements
+- **Complete Save.cs Implementation**: All major methods from ZScream's Save.cs now implemented in YAZE
+- **Area Size Support**: Full support for Small, Large, Wide, and Tall area types with proper transitions
+- **Interactive Overlays**: Complete overlay save system matching ZScream's functionality  
+- **Custom ASM Integration**: Proper handling of ZSCustomOverworld ASM versions 1-3+
+- **Memory Layout**: Correct usage of expanded vs vanilla memory locations based on ROM type
 
 ## 0.3.0 (September 2025)