assertAccountsOwner refused a symlink or non-directory on the config path,
but checked owner and mode only on the leaf. An ancestor owned by another
user, or writable by others without the sticky bit, let that user rename the
directory away and put their own accounts.json in its place. Since M3 that
file decides root authority on a deployed Console.
One shared helper, config-dir-trust.mjs, now holds A2's rule: every ancestor
belongs to root or this uid and is group or other writable only with the
sticky bit; configDir itself is this uid's and not group or other writable.
The accounts store (load, init, lock, locked write, mosaic accounts) and the
root agent file's writer both call it, each with its own refusal code. A2's
messages are unchanged.
Accounts refusals no longer quote a path: the config directory and accounts
file uid messages name the rule and the uid only (redaction rule, #1916).
A missing config directory now refuses accounts-unsafe instead of a raw
ENOENT.
jason.woltje