Pack only runtime shader libraries, reflection JSON and TSV tables, excluding translated Metal sources and _b_build.json from the app and its free-space estimate.
The original 2,000-file batching still exceeded the macOS exec limit with valid long paths. Budget encoded arguments, inherited environment and pointer overhead instead, with regression coverage for long and multibyte paths, clone flags and an exhausted argument budget.
Validation: reproduced E2BIG before the fix; all 17 Mac app tests and 4 documentation tests pass on current main. Tests use synthetic files and a stand-in host; a full large-game packaging run remains untested.
Co-authored-by: 7splay <107197512+7splay@users.noreply.github.com>
