bun in -e mode swallows uncaught exceptions thrown after a require() and
exits 0 (verified on 1.3.13; uncaughtException handlers never fire either),
so any runtime throw in a mutator was a SILENT SUCCESS. Every script body
now runs inside a gsMain try/catch that prints "internal error ... refusing
to mutate" and exits 4.
Also: lock give-up now exits 5 instead of 0 (callers must not report a
skipped mutation as registered); basename lookup uses hasOwnProperty so a
foreign hook named "toString"/"constructor" can't resolve to an inherited
Object.prototype member and abort the sweep; ownership-checked release also
clears an empty/missing owner file; backup rotation sorts by mtime, not
name; Windows-only backslash normalization (a legal Unix path containing a
backslash is no longer rewritten); GSTACK_SWEEP_EXCLUDE_SOURCES lets a
sweep spare named sources; lock tradeoffs documented at the lock helper.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>