Add DistributedDirectMemory for multi-drive memory distribution

[konard]

Summary

This PR implements the DistributedDirectMemory class as requested in issue #21, enabling memory distribution across multiple storage locations (drives or machines).

Key Features

• Multi-drive support: Distributes memory segments across different storage locations
• Seamless API: Extends ResizableDirectMemoryBase with consistent interface
• Cross-segment operations: Transparent read/write operations across segment boundaries
• Dynamic scaling: Automatic segment creation and cleanup based on capacity changes
• Comprehensive testing: 12 unit tests covering all functionality

Technical Implementation

• Architecture: Segments are distributed round-robin across provided base paths
• Segment management: Automatic creation/disposal of FileMappedResizableDirectMemory segments
• Memory access: Provides both direct pointer access and buffer-based I/O methods
• Capacity handling: Supports dynamic resizing with proper segment cleanup

Use Cases

✅ Multi-drive memory distribution - Primary use case from issue #21
🔄 Multi-machine memory distribution - Foundation for future network-based distribution

Changes

• New class: DistributedDirectMemory with full documentation
• Comprehensive tests: DistributedDirectMemoryTests with 12 test cases
• Project updates: Version bump to 0.5.0 and dependency additions
• Package tags: Added DistributedDirectMemory to NuGet package tags

Testing

All tests pass successfully:

• ✅ Constructor validation and directory creation
• ✅ Capacity management and resizing
• ✅ Basic and cross-segment read/write operations
• ✅ Multi-segment distribution verification
• ✅ Random access patterns
• ✅ Large data handling
• ✅ Resource cleanup and disposal
• ✅ Argument validation
• ✅ Pointer-based access

🤖 Generated with Claude Code

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Resolves #21