packing-records: candidate improvements to four packing record tables

1,050 explicit configurations that improve entries in four public record tables for packing problems: 731 in Henry Cohn's table of Grassmannian packings, 52 on the Game of Sloanes leaderboard of complex line packings, and 108 (equal 4-D spheres in a 4-D sphere) and 159 (equal spheres in a cube) in Eckard Specht's Packomania tables. Each beats its table entry by at least 1e-7 in the table's own measure; the Packomania results also beat a local LP polish of the posted configuration by at least 1e-7. The tables were read on 2026-10-31 and 2026-11-01. The record keepers have not reviewed these results. The archive contains the coordinate files in each table's own format, cells.csv (values, margins, polish floors, sha256, and the author of any posted configuration a search started from), fact extracts of the four tables, and a Python standard-library checker that recomputes every value with exact rational arithmetic (sh check/check_all.sh). Found by Benjamin Meadows with Claude AI, using numerical optimization (smoothed-maximum descent, Riesz-energy relaxation, basin hopping, large-neighborhood search and sequential LP polish) run on cloud machines. Snapshot of https://github.com/TheBenMeadows/packing-records at commit abeefc5.