Implement streaming HDiffPatch-style binary differ with memory limit

[JusterZhu]

Summary

Implement a new streaming binary differ inspired by HDiffPatch concepts, replacing BSDIFF's full-memory approach with sliding-window streaming.

Scope

• \StreamingHdiffDiffer\ implementing \IBinaryDiffer\
• Content-defined chunking (CDC) with rolling hash for block-level matching
• Sliding window with configurable memory limit (default 64MB)
• Two-level matching: fast block match + fine-grained byte adjustment
• Separate chunk stream for parallelism-ready output

Expected Improvements

• Memory: O(windowSize) instead of O(fileSize × 17)
• Supports arbitrarily large files (GB+)
• Patch size: 30-50% smaller than BSDIFF for binary files (executables, DLLs)
• Diff speed: 2-5x faster with block-level pre-filtering

Dependencies

• Requires Refactor Differential: Abstract interfaces for pluggable differs and compression #258 (interface abstractions)