Run Perplexity search and auth requests through pi's Node runtime instead of
shelling out to Bun. Move development and CI commands to npm, add a Node test
build path, and keep OTP auth fail-fast when Set-Cookie headers are not
available.
Enforce 0600 permissions after every auth token write so existing files
with broader modes are corrected.
Add a regression test for the permission hardening path and document the
Bun runtime dependency used by the Node/jiti search subprocess path.
Also declare bun in package dependencies and engines.
Ivan Pereira