Address review findings on the CPython backend:
- CRITICAL: a model program could leave a descendant in the child's own
process group that ignores SIGTERM but releases the inherited pipes, so
the leader's `close` fired and settle() cancelled the pending SIGKILL
before it escalated — run()/dispose() returned while that child lived.
kill() now unrefs the grace timer and settle() no longer clears it, so
the SIGKILL reaches the whole group; killGroup swallows ESRCH when the
group is already gone (the normal case). Adds a real-subprocess
regression test.
- WARNING: the maxLogBytes/maxValueBytes load bound divided the frame
ceiling by 6 for escape expansion, but both budgets are metered in
already-escaped serialized bytes, so a payload occupies at most
cap+envelope on the wire. Bound is now ceiling-envelope; drop the unused
escape constant.
- Narrow the runtime.spec.ts header to "no subprocess mocks" (it mocks
node:fs.copyFileSync for staging-failure cases).
- Use full-width punctuation in the README.zh.md prose per translation
rules; re-record the pair.
Land the PythonCodeRuntime implementation on top of the fd-3 protocol
seam: python3 -I per run, binding namespace over fd 3, RLIMIT_CPU/AS,
wall-clock timer, and SIGTERM->grace->SIGKILL process-group teardown,
with the real-subprocess integration suite.
Fixes three defects surfaced on the source PR's review before they ship:
- boot-write failure resolved a worker-exit through finish()/settle()
that read wallTimer/onAbort/live in their TDZ, rejecting run() instead;
the boot write now runs after those bindings and the v8-ignore that hid
the branch is removed.
- log capture serialized against settlement with no lock while model
daemon threads keep writing; LogBuffer now owns one shared re-entrant
lock taken by write/flush_line/push.
- the fd-3 line residual was a subarray view pinning the whole joined
frame; it is copied into a right-sized Buffer via detachResidual so
pendingBytes measures what is retained.
Chinesezjc