Play Framework

Honor .gitignore in play dist and enable preview in javadoc

Play dist now uses git ls-files to respect .gitignore files (including
subdirectory .gitignore) when inside a git repo, falling back to
hardcoded exclusions otherwise. Also adds --enable-preview --source 25
to javadoc options for Java preview feature support.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>