Adds Cantor (Jourdain 1915 transl., PD), De Morgan First Notions of
Logic (PG #67017, PD), Russell Introduction to Mathematical Philosophy
(PG #41654, PD), and Judson Abstract Algebra Theory and Applications
(GFDL-1.3) to the textbook manifest, plus per-book make targets +
a `textbooks-base-knowledge` bulk target. Idempotent at DB layer.
These four primaries cover the proprietary citations across pillars
I/II/III/IX (Mendelson, Enderton, Jech, Barendregt, Dummit-Foote)
that dominate the 74 unresolved claim-pack records. They land as
honest "no match" under the existing resolver `_shard_matches_citation`
heuristic (cited-author surname required) — full lift gates on
fox citation-alias decisions per #000041.
Total ingest delta: 43 docs / 295 chunks across four crawl shards.
Bench journal under bench/results/textbook-base-knowledge-upgrade-2026-05-09.md
records per-book license rationale, projected lift table, and the
remaining #000038 acquisition gaps (Hilbert-Ackermann, Landau,
Gödel, Kolmogorov, Church) for which no clean PD HTML edition was
located in this session.