Remove only the token fields from the config file, preserving everything else (the CLI's deviceId etc. survive a logout). No-op when the file does not exist.
Read the token fields from the config file. Returns null when the file
does not exist or contains no token fields. expiresAt is derived from
the idToken's JWT exp claim, not stored separately. Read errors other
than a missing file (and invalid JSON) propagate.
Merge the provided token fields into the config file (read-modify-write;
all non-token fields and any token field not present in creds are kept).
Creates the parent directory (mode 0700) and writes the file with mode
0600 — this mutates the host filesystem.
@edgible-team/sdk/node — Node-only platform pieces (D4).
These are included automatically in the node-conditioned root build's defaults; this subpath exposes them by name for consumers that wire their own stores/providers (the CLI in Phase 6, tests).