feat: add configurable fast_model for declarative providers (#8194)

Signed-off-by: rdondeti <ravitez.dondeti@gmail.com>
Signed-off-by: Douwe Osinga <douwe@squareup.com>
Co-authored-by: Douwe Osinga <douwe@squareup.com>

ui/desktop/src/api/types.gen.ts

@@ -216,6 +216,7 @@ export type DeclarativeProviderConfig = {
     dynamic_models?: boolean | null;
     engine: ProviderEngine;
     env_vars?: Array<EnvVarConfig> | null;
+    fast_model?: string | null;
     headers?: {
         [key: string]: string;
     } | null;