fix(web): answer the review on the declared-provider editor

The display name read only the user layer while its placeholder claimed a
cleared field falls back to the route id. A `cordis.yml` can pin a name
for a route the catalog does not ship, and clearing then restores that
name, not the id. The placeholder now reads the composition layer — the
same layer `inheritedModels` reads — and names the route id only when
nothing pins one.

The saved notice echoed the target captured when the card opened, which
never lied while the name could not change. It now names the provider as
the refreshed directory reports it, and is announced only once that
refresh is in the snapshot it reads from.

The protocol select's blank option is named, because a screen reader
announces it either way and an unnamed one is a choice with no identity.
`protocolChoices` no longer rehydrates the section schema for the two
layouts that have no per-route protocol to find.

Documentation caught up with the same broom: the module JSDoc and the
e2e header both still described one field where the fold now carries
two, the English user guide carried a Chinese UI label among English
ones, and the README's DeepSeek row inventory omitted `maxTokens`.

docs/user/guide/providers.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/user/guide/providers.md
-providers.md: fff2e9f66b1dcec2b549420ee43f908043983338
+providers.md: b5217ca7eaa00e7f31db4b3269ddb0d489fe3923
 providers.zh.md: a27adefdbb76c43d099982b0503a9adde139597f