Wrap spawn and the fd-3 narrowing so a synchronous throw (ENAMETOOLONG on
an over-PATH_MAX pythonBin, EMFILE) removes the run's staging directory and
resolves the same worker-exit class as the async error event, instead of
rejecting run() and leaking the directory.
Aggregate native stdout/stderr by real newline rather than by Node data
chunk: logs entries are joined with "\n" downstream, so a newline-free
write larger than one pipe read no longer reads back with spurious breaks.
The ledger still bounds a newline-free flood.
Track a running scan offset in both frame readers so a large frame
accumulated across chunks is scanned once, not re-scanned from 0 per chunk.
Reword the deadline hard-bound v8-ignore to state its real environment
dependence (PID-1-doesn't-reap container, zombie survivor) and cross-ref
the note's rejected signal-0 alternative; fix settle comments that quoted
the pre-qualification teardown contract; document the capMessage vs
_cap_message billing split on both sides; guard the dispose-after-resolve
heartbeat assertion against a vacuous 0===0 pass; reuse
_TRUNCATION_MARKER_BYTES; note the abandoned-call pending-entry bound.
Update the Agent Note Decision/Testing/Alternatives/Consequences for the
above and record the confirmed-empty finalize as a second honest
fail-before exception; sync the zh pair.