- Decide the profile claim when the row is written (the check from #101827)
and drop the None sentinel from #103712. On current main load_pool() leaves
a profile that borrows from an empty root at the default, so the sentinel
alone never reached the claim path (its test stays red).
- add_entry() re-reads the store after writing. A missing row raises
CredentialNotSavedError; `hermes auth add` exits with that message instead
of printing "Added", and the dashboard pool endpoint returns it as a 400.
- Tests: the two contributor tests become one invariant over every
SINGLE_USE_REFRESH_POOL_PROVIDERS provider (the row is readable, root
auth.json is byte-identical), plus the CLI success-line contract.
- Docs: profiles page, EN and zh-Hans.
Fixes#103694
(cherry picked from commit 0e250a005a3353564642ce70f100d89174a583f2)
dc824c5f65