feat(ui-models): schema-driven provider configuration page

The Models settings section joins llm.providers (the configurable
directory with live state), settings.describe (schemas, layered redacted
values, secret slots), and credentials.describe (value-free badges) into
provider rows with one editor card at a time. The editor renders the
provider's profile subtree through dsh-client-schema-form; the
credential-ref role mounts a control that shows configured/source state
and stores keys write-only through credentials.set. Apply without
removals merges a minimal patch (stored secrets outside it survive);
apply after a reset — and row deletion — replace the user section so
removals land. The client runtime bridges the three new host frames to
typed ctx events (settings/credentials/models changed), the page
refetches on any of them once loaded, and ui-model's per-session picker
directories reload on models/changed so a settings-born route appears in
open pickers without a reopen.

pnpm-lock.yaml

@@ -1194,18 +1194,27 @@ importers:
 
   packages/client/ui-models:
     devDependencies:
+      '@deepseek-ai/dsh-client-connection':
+        specifier: workspace:^
+        version: link:../connection
       '@deepseek-ai/dsh-client-locale':
         specifier: workspace:^
         version: link:../locale
       '@deepseek-ai/dsh-client-runtime':
         specifier: workspace:^
         version: link:../runtime
+      '@deepseek-ai/dsh-client-schema-form':
+        specifier: workspace:^
+        version: link:../schema-form
       '@deepseek-ai/dsh-client-ui-settings':
         specifier: workspace:^
         version: link:../ui-settings
       '@deepseek-ai/dsh-client-ui-slots':
         specifier: workspace:^
         version: link:../ui-slots
+      '@deepseek-ai/dsh-client-web-react':
+        specifier: workspace:^
+        version: link:../web-react
       '@deepseek-ai/dsh-invariants':
         specifier: workspace:^
         version: link:../../support/invariants