Fixes#2698 — The two separate LF/CRLF .replace() calls in the Codex hooks
migration could not handle mixed line endings (e.g. header in LF, body in
CRLF), leaving stale gsd-update-check blocks after reinstall. Consolidated to
a single \r?\n-aware regex with gm flags that handles LF, CRLF, and mixed
content in one pass.
Fixes#2678 — installSdkIfNeeded() called process.exit(1) unconditionally when
sdk/dist/cli.js was missing, even during --local installs where users cannot
write to global node_modules. Added isLocal option: when true, prints a warning
and returns instead of exiting.
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>