Advanced research and repository improvements

[consigcody94]

This major update introduces a complete modern C++ architecture:

Core Library (include/keyhunt/core/)

• logger.h: Thread-safe logging with multiple sinks, file rotation
• error.h: Exception hierarchy with source location, nested exceptions
• config.h: Type-safe configuration management with JSON/env support
• memory.h: RAII wrappers, aligned allocators, secure memory handling
• thread_pool.h: High-performance thread pool with priorities
• types.h: Type-safe abstractions (UInt256, Hash256, KeyRange, etc.)
• bsgs.h: Clean BSGS algorithm interface with CPU/CUDA backends
• bloom_filter.h: Modern bloom filter with cascading support
• security.h: Input validation, secure comparison, rate limiting
• simd.h: Cross-platform SIMD (ARM NEON, x86 SSE/AVX)
• dashboard.h: Web-based real-time monitoring dashboard
• distributed.h: Multi-GPU and distributed computing coordination

Testing & Benchmarks

• tests/: Comprehensive unit test suite (types, memory, threads, bloom)
• benchmarks/: Performance benchmarking for all core operations

CI/CD Improvements

• Enhanced GitHub Actions with lint, security scan, ARM64 builds
• macOS Apple Silicon support (M1/M2/M3/M4)
• Documentation generation with Doxygen
• Automatic release generation with artifacts

Build System

• Updated CMakeLists.txt with test/benchmark/docs targets
• ARM64 Docker build support