fix(ollama): add missing api field to auto-discovered models

Auto-discovered Ollama models from discoverOllamaModels() were missing
the `api` field, causing "Unhandled API in mapOptionsForApi: undefined"
errors when the model was used at runtime.

This adds `api: "openai-completions"` to match the provider-level
configuration in buildOllamaProvider().

Fixes #3153

src/agents/models-config.providers.ts

@@ -120,6 +120,7 @@ async function discoverOllamaModels(): Promise<ModelDefinitionConfig[]> {
         cost: OLLAMA_DEFAULT_COST,
         contextWindow: OLLAMA_DEFAULT_CONTEXT_WINDOW,
         maxTokens: OLLAMA_DEFAULT_MAX_TOKENS,
+        api: "openai-completions",
       };
     });
   } catch (error) {