fix(core): resolve hidden title models internally

packages/core/test/catalog.test.ts

@@ -411,6 +411,9 @@ describe("CatalogV2", () => {
       })
 
       expect((yield* catalog.model.small(providerID))?.id).toBe(ModelV2.ID.make("gpt-5.4-nano"))
+      expect((yield* catalog.model.available()).some((model) => model.id === ModelV2.ID.make("gpt-5.4-nano"))).toBe(
+        false,
+      )
     }),
   )
 

packages/core/test/plugin/provider-github-copilot.test.ts

@@ -289,6 +289,28 @@ describe("GithubCopilotPlugin", () => {
     }),
   )
 
+  it.effect("pins picker-hidden utility models for internal small-model work", () =>
+    Effect.gen(function* () {
+      const catalog = yield* Catalog.Service
+      const providerID = ProviderV2.ID.githubCopilot
+      yield* catalog.transform((catalog) => {
+        catalog.provider.update(providerID, () => {})
+        catalog.model.update(providerID, ModelV2.ID.make("gpt-4.1"), (model) => {
+          model.enabled = false
+        })
+        catalog.model.update(providerID, ModelV2.ID.make("gpt-5.4-nano"), (model) => {
+          model.enabled = false
+        })
+      })
+      yield* addPlugin()
+
+      expect((yield* catalog.model.small(providerID))?.id).toBe(ModelV2.ID.make("gpt-5.4-nano"))
+      expect((yield* catalog.model.available()).some((model) => model.id === ModelV2.ID.make("gpt-5.4-nano"))).toBe(
+        false,
+      )
+    }),
+  )
+
   it.effect("does not disable gpt-5-chat-latest for non-Copilot providers", () =>
     Effect.gen(function* () {
       const catalog = yield* Catalog.Service

packages/core/test/session-title.test.ts

@@ -55,6 +55,21 @@ const models = Layer.mock(SessionRunnerModel.Service)({
       : model
     return Effect.succeed(SessionRunnerModel.resolved(selected))
   },
+  resolveCatalogModel: (session, selected) => {
+    resolvedModels.push({ id: selected.id, provider: selected.providerID })
+    if (failSmallResolve && selected.id === ModelV2.ID.make("mini")) {
+      return Effect.fail(new Error("small unavailable") as never)
+    }
+    return Effect.succeed(
+      SessionRunnerModel.resolved(
+        Model.make({
+          id: selected.id,
+          provider: selected.providerID,
+          route: OpenAIChat.route.with({ limits: { context: 10_000, output: 1_000 } }),
+        }),
+      ),
+    )
+  },
 })
 const it = testEffect(
   AppNodeBuilder.build(
@@ -152,9 +167,11 @@ const seedSmallModel = () =>
         model.time.released = Date.now()
       })
       catalog.model.update(providerID, ModelV2.ID.make("mini"), (model) => {
+        model.enabled = false
         model.family = ModelV2.Family.make("gpt-nano")
         model.time.released = Date.now()
       })
+      catalog.model.small.set(providerID, ModelV2.ID.make("mini"))
     })
   })