Reproduction package for: Geometric support and cutting-direction mixing in cross-source validation of milling stability

This deposit contains two items: (1) the reproduction package, and (2) the manuscript PDF. Reproduction package: data/ — 241 files, including the nominally stable evaluation domain (664 source records, 376 evaluation points, 86 experimental chatter points), paired train/test identities, point-level scores, direction and stable-label support summaries, continuous-coverage certificates, speed-block splits, fixed-budget verification queues, Eynian boundary comparisons, auxiliary diagnostics, and the v2.1 addendum (Eynian three-flute slot-milling target coverage check; 60-system synthetic validation of the contextual mixing bound, seeds fixed); scripts/ — 120 Python scripts, including computation entry points for each table and figure; EVIDENCE_MAP_CN.md and claim_file_manifest.json — claim-to-file mapping with SHA256 digests; HASHES.txt — SHA256 manifest for all package files. Manuscript: "Geometric support and cutting-direction mixing in cross-source validation of milling stability" (Yulong Li, Yang Sicong, Independent Researchers, Guiyang, China), v1.1 with Proposition 1, a fifth public target (Eynian slot-milling boundary), and synthetic-system validation; companion to the data package, under consideration at a journal. Software environment: Python 3.14.4, NumPy 2.5.1, SciPy 1.18.1, scikit-learn 1.9.0. Notes: the scripts carry historical path conventions and are not a one-click rerun; inputs must be re-pointed explicitly (see README). Third-party original datasets and third-party code repositories are not redistributed. Code is licensed MIT and data/documentation CC BY 4.0; this record is licensed CC BY 4.0.