The Codex settings copy implied the cached credential was app-private. It is
a normal login-Keychain item: reachable by programs running as you, with no
per-app ACL. The real win is that it is no longer a world-readable 0644 file,
so say that instead.
Also documents why readAfterSecuringPermissions repairs permissions before
validating content (validating first would read the secret while it is still
world-readable, which is the window the function exists to close), and why the
Keychain service names are deliberately not derived from CFBundleIdentifier
(the Electron app hardcodes the same strings).
Adds the #1037 changelog entry.
Extra High MERGE AFTER FIX on 252ea92. Pathname chmod was
unverified. Disconnect hid retry when only the legacy file
survived. Secure read stopped at exactly maxBytes.
Tighten leftovers via opened-fd fchmod+fstat. Keep bootstrap
unless both Keychain and legacy deletes succeed. Read
maxBytes+1 so growth past the limit is rejected.
A valid Keychain item plus a leftover JSON used to skip chmod, so a
failed unlink could leave 0644 secrets on disk. Failed Disconnect also
cleared bootstrap and hid the retry. Repair leftover files to 0600,
keep bootstrap when Keychain delete fails, revalidate the opened fd,
and loop the secure read.
Stop writing OAuth caches as Application Support JSON. Persist
CodeBurn-owned items in Keychain, secure-read and migrate leftover
0644 files only after read-back verification, and keep Claude from
storing a refresh token.
