Advanced ComposeFS Features - Updated documentation and marked Phase 2.3 as completed

src/apt-layer/CHANGELOG.md

@@ -1450,3 +1450,65 @@ This project is part of the Particle-OS system tools and follows the same licens
 - Advanced dependency resolution
 - Performance optimization
 - Enterprise features
+
+## [Unreleased] - Phase 2.3: Advanced ComposeFS Features
+
+### Added
+- **Phase 2.3: Advanced ComposeFS Features** - Multi-layer composition, optimization, and enhanced metadata
+  - `compose_multiple_layers()` - Support for more than 2 layers in composition
+  - `resolve_conflicts_interactive()` - Advanced conflict resolution with interactive mode
+  - `deduplicate_layer()` - Layer deduplication with content-hash strategy
+  - `compress_layer()` - Layer compression (gzip, zstd, xz)
+  - `handle_enhanced_metadata()` - Enhanced metadata with JSON/YAML formats
+  - `benchmark_layer()` - Layer performance benchmarking
+  - `track_layer_relationships()` - Layer relationship tracking and genealogy
+  - `cleanup_multiple_mounts()` - Efficient cleanup for multi-layer operations
+
+### New Commands
+- `apt-layer composefs multi-compose <layer1> <layer2> ... <output-layer>` - Multi-layer composition
+- `apt-layer composefs deduplicate <input-layer> <output-layer> [strategy]` - Layer deduplication
+- `apt-layer composefs compress <input-layer> <output-layer> [type] [level]` - Layer compression
+- `apt-layer composefs benchmark <layer-path> [benchmark-file]` - Layer performance benchmarking
+- `apt-layer composefs resolve-conflicts <base-layer> <new-layer> <output-layer> [conflict-file]` - Advanced conflict resolution
+- `apt-layer composefs track-relationships <layer-path> <relationship-file> [parent-layers...]` - Layer relationship tracking
+- `apt-layer composefs enhanced-metadata <source-dir> <metadata-file> [format]` - Enhanced metadata generation
+
+### Features
+- **Multi-Layer Composition**: Support for unlimited layers with optimized overlay filesystem
+- **Advanced Conflict Resolution**: Interactive conflict resolution with diff viewing and manual merge options
+- **Layer Deduplication**: Content-hash based deduplication with space savings reporting
+- **Layer Compression**: Multiple compression formats (gzip, zstd, xz) with configurable levels
+- **Enhanced Metadata**: JSON/YAML metadata with comprehensive file statistics and content hashes
+- **Performance Benchmarking**: Mount time, read speed, and compression ratio measurements
+- **Layer Relationship Tracking**: Complete genealogy tracking with parent-child relationships
+- **Memory-Efficient Operations**: Optimized for large layer handling with minimal memory footprint
+
+### Technical Implementation
+- Enhanced scriptlet: `05-composefs-integration.sh` with 800+ additional lines of advanced functionality
+- Multi-layer overlay filesystem composition with proper layer ordering
+- Content-hash based deduplication with hardlink optimization
+- Multiple compression algorithms with performance metrics
+- JSON/YAML metadata generation with validation
+- Performance benchmarking with detailed metrics collection
+- Layer relationship tracking with JSON metadata
+- Comprehensive error handling and transaction support
+
+### Testing
+- Created comprehensive test suite: `test-advanced-composefs.sh`
+- 8 test cases covering all advanced functionality
+- Multi-layer composition validation
+- Deduplication and compression testing
+- Performance benchmarking validation
+- Enhanced metadata format testing
+- Relationship tracking validation
+- Advanced conflict resolution testing
+
+### Configuration
+- Configurable compression types and levels
+- Deduplication strategy options
+- Metadata format selection (JSON/YAML)
+- Performance benchmarking thresholds
+- Conflict resolution strategies
+- Interactive vs non-interactive modes
+
+## [Unreleased] - Phase 2.2: Basic ComposeFS Integration ✅ COMPLETED