Resolved issues rasied #1611 , #1628 , #1602

[cropsgg]

here are the solutions that I did :

1. /sync-gbrain --full on ~100k-page brains reliably exceeded the
   hard-coded 35-minute timeout, SIGTERMed mid-import, and lost the staging
   checkpoint. Set GSTACK_SYNC_MEMORY_TIMEOUT_MS (or CODE for the code
   stage) to override; bad input falls back to the 35-min default with a
   stderr warning so a typo can't silently disable the safety net.

2. Codex CLI defaults to gpt-5.2-codex, which OpenAI's ChatGPT-account
   entitlement filter rejects with a 400 ("model is not supported when
   using Codex with a ChatGPT account"). Every skill that shells out to
   codex — /codex, /autoplan, /plan-eng-review, /ship, /plan-ceo-review,
   /plan-design-review — broke for ChatGPT-only auth users.

Add _gstack_codex_account_kind (apikey | chatgpt | none) and
_gstack_codex_default_model_args to bin/gstack-codex-probe. Templates
expand $_CODEX_MODEL_ARGS=$(_gstack_codex_default_model_args) before
every codex invocation; API-key users get nothing extra, ChatGPT users
get -m gpt-5.2. $GSTACK_CODEX_MODEL overrides; set to "default" to
opt out of injection entirely.

Wired at all 9 callsites across codex/SKILL.md.tmpl (5) and
autoplan/SKILL.md.tmpl (4). A static template guard test catches a
future edit that drops the variable.

3. Issue Windows: bun run build aborts — package.json build script uses redirection constructs bunsh rejects; regression test only checks statically #1602 package.json fix landed in v1.42.0.0 Daegu wave: 23 community-filed bugs + PTY classifier enforcement (24 bisect commits) #1594, but the regression test
   was string-matching only. Exercise scripts/build.sh and
   scripts/write-version-files.sh via bash -n (syntax check) and a real
   invocation against tmpdir targets; also expand the package.json guard
   to cover every bunsh-incompatible construct (subshells-with-redirection,
   multi-redirection, brace groups, process substitution) in one place.
   Catches a future edit that re-introduces any of them without needing a
   Windows runner.

if useful kindly merge