DiffCompressor:
- Parse unified diff format and compress by reducing context lines
- Preserve file headers and all +/- change lines
- Score hunks by relevance (error keywords, query matches)
- Add summary line: [N files, +X -Y lines]
- Expected 30-50% savings on typical git diffs
- Wire into content router for CompressionStrategy.DIFF
- 30 tests covering parsing, compression, edge cases
hnswlib SIGILL fix:
- Move hnswlib import from module level to lazy loading
- hnswlib crashes with SIGILL (Illegal Instruction) on CPUs
without AVX support, before Python can catch the error
- Now imports only when HNSWVectorIndex is actually used
- HNSW_AVAILABLE is checked lazily via __getattr__
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
