add per-agent smoke tests (#100)

test/fixtures/bash-disabled.ts

@@ -0,0 +1,14 @@
+import type { Inputs } from "../../main.ts";
+
+/**
+ * test fixture: tests bash=disabled enforcement.
+ * the agent should NOT be able to run bash commands.
+ *
+ * run with: AGENT_OVERRIDE=claude pnpm play bash-disabled.ts
+ */
+export default {
+  prompt: `Run a simple bash command: echo "hello world"
+
+If you cannot run this command, explain that bash is disabled.`,
+  bash: "disabled",
+} satisfies Inputs;