feat(ui-models): tag the provider rows this deployment declared

A row's stored profile could not tell a hand-declared gateway from a
shipped provider whose models someone narrowed — both look identical from
outside the adapter — so the Models page had no way to mark the routes a
deployment added itself.

The directory entry now carries `declared`, answered by the owning adapter
against its own installed catalog, and the page renders a Custom tag from
it. Absence stays "this adapter draws no such distinction" rather than
"shipped", so a route no adapter claims is labelled neither way.

Also records the default-route work's Agent Note and the e2e evidence for
all three changes: the composer switch writing the section, and the Models
page declaring a route with its own reasoning effort.

tsconfig.host.json

@@ -9,6 +9,7 @@
   },
   "include": [
     "apps/web/tests/scaffold.ts",
+    "apps/web/tests/default-model.e2e.ts",
     "apps/web/tests/support.ts",
     "apps/web/tests/scaffold-hermetic.e2e.ts",
     "apps/web/tests/core-web-profile.snapshot.ts",