Migrate to multi-file architecture: smarter chunking + fixed RERANK_LIMIT
index: message-based windowed chunking (5 msgs/1h gap), better unicode
cleaning, separate dense (with timestamps)/sparse content renderers,
BM25 preload on startup, ThreadPoolExecutor(4), UVICORN_WORKERS=4,
Dockerfile copies all *.py
search: proper multi-module structure (query_builder, retrieval, rerank,
aggregation), RERANK_LIMIT 60→15 (fixes 429 errors), extra dense vectors
for variants/hyde, date+asker metadata filters, httpx pool (100/20/30s),
BM25 preload on startup, Dockerfile copies all *.py
68/68 unit tests passing
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
e468c4768b