Owner review of p5b (tasks 01-03 by Ornith):
- background.go: `seen` was never cleared, so a document whose background embedding failed
(Dixie hiccup) or was abandoned could never be queued again: every later question on it stayed
BM25 for the life of the process. Dedupe now covers only queued and in-progress documents.
- background.go: acquireGate gave up after one retry and dropped the document; the task said to
keep retrying once a second. It now waits (background work has no deadline).
- retrieval.go/background.go: a vector the server left out is not cached as an empty vector.
- bm25.go: Scores on a nil *BM25 dereferenced it; returns nil.
Regression tests in review_test.go; both fail on the old code.
End-to-end against Dixie (local serve): Karpathy's thesis, 95 pages / 51 chunks: bm25 in 19 s,
hybrid (51 embedded) after the background; RP2040 datasheet, 642 pages / 284 chunks (a 422
before P5b): bm25 in 13.5 s, all 284 embedded within 90 s, hybrid answer correct with its quote.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
SplitPages is Split's budget/line splitting plus page awareness: a "--- page N ---"
line sets the current page and a chunk that starts after the first marker but not on
a marker line is prefixed "--- page N (cont.) ---\n\n" for the page its first line
belongs to, so every chunk names its page. BM25 (k1=1.2, b=0.75) ranks chunks
lexically with counted term frequencies and ln(1+(N-df+0.5)/(df+0.5)) IDF.
Co-Authored-By: ornith-1.5-35b-a3b <ornith-1.5-35b-a3b@llama.cpp.invalid>
kyleandClaude Opus 5.5
