Codex and the other env-var hosts run each block in a fresh shell, so
GSTACK_ROOT/BIN, B and D set by the preamble were empty in later blocks
(/bin/gstack-slug, B=/browse). scripts/resolvers/runtime-root.ts now owns
root resolution: a valid exported GSTACK_ROOT (bin/ and lib/), else the
per-install literal root (no git call), else repo-local, else the global root
(CODEX_HOME on Codex); no root prints the setup fix line and exits. One
post-render pass inserts it (<=400 bytes) into every fence that uses these
variables without assigning them; B/D come from the same helper as BROWSE
and DESIGN SETUP. Claude output is byte-identical.
Migrated pins of the old preamble lines (gen-skill-docs.test.ts) and a
fixture whose exported GSTACK_ROOT lacked lib/ (skill-positional-literals).
garrytan
c050f18371