v0.1.3 — Float placement, keywords and arXiv source

• Keep all figures and tables before References with float barriers, and move float declarations closer to their first discussion.
• Add the requested keywords immediately after the abstract. The rebuilt paper is seven pages.
• Include the regenerated, comment-stripped arXiv source ZIP. A fresh extraction compiles with pdflatex only; extracted text, external links and every rendered page match the release PDF.

No scientific numbers, claims, figure contents or results changed from v0.1.2. No new inference or cloud compute.

Validation: all 36 tests pass; pip-audit reports no known vulnerabilities in 87 dependencies; 56 executed source files verify. All six floats are on pages 2, 4 and 5; References starts on page 6. All 18 PDF links resolve, and the former repository URL redirects. See SHA256SUMS, arxiv-validation.json and v0.1.3_verification.json for checksums and evidence.