fix: oven papers build — add CJK fonts + fix deploy permissions
deploy.sh: Added texlive-lang-chinese and texlive-lang-cjk to TeX Live install. These provide xeCJK package needed for Chinese translations. Without them, all zh .tex files fail with "Emergency stop" at \setCJKmainfont.
papers-builder.mjs: Added chmod -R u+w on the deploy directory before running publish. PDFs committed locally by developers may have restrictive permissions that prevent the oven process from overwriting them during deployment.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>