fix(test): guard model resolution profiler args

test/scripts/issue-78851-model-resolution.test.ts

@@ -0,0 +1,43 @@
+// Issue 78851 profiler CLI tests cover argument handling before work starts.
+import { spawnSync } from "node:child_process";
+import { describe, expect, it } from "vitest";
+
+function runProfiler(...args: string[]) {
+  return spawnSync(
+    process.execPath,
+    ["--import", "tsx", "scripts/perf/issue-78851-model-resolution.ts", ...args],
+    {
+      cwd: process.cwd(),
+      encoding: "utf8",
+    },
+  );
+}
+
+describe("issue 78851 model resolution profiler CLI", () => {
+  it("prints help without starting the profiler", () => {
+    const result = runProfiler("--help");
+
+    expect(result.status).toBe(0);
+    expect(result.stdout).toContain("OpenClaw issue #78851 model-resolution profiler");
+    expect(result.stdout).toContain(
+      "node --import tsx scripts/perf/issue-78851-model-resolution.ts [options]",
+    );
+    expect(result.stderr).toBe("");
+  });
+
+  it("rejects unknown arguments before starting the profiler", () => {
+    const result = runProfiler("--wat");
+
+    expect(result.status).toBe(1);
+    expect(result.stdout).toBe("");
+    expect(result.stderr.trim()).toBe("Unknown argument: --wat");
+  });
+
+  it("rejects partial numeric arguments before starting the profiler", () => {
+    const result = runProfiler("--providers", "48junk");
+
+    expect(result.status).toBe(1);
+    expect(result.stdout).toBe("");
+    expect(result.stderr.trim()).toBe("--providers must be a positive integer");
+  });
+});