fix(ai): clamp streamSimple max tokens

Clamps streamSimple max-token defaults against estimated context, addressing #5595.

closes #6061

packages/ai/src/api/google-generative-ai.ts

@@ -290,7 +290,7 @@ export const streamSimple: StreamFunction<"google-generative-ai", SimpleStreamOp
 		throw new Error(`No API key for provider: ${model.provider}`);
 	}
 
-	const base = buildBaseOptions(model, options, apiKey);
+	const base = buildBaseOptions(model, context, options, apiKey);
 	if (!options?.reasoning) {
 		return stream(model, context, { ...base, thinking: { enabled: false } } satisfies GoogleOptions);
 	}