test(pcap): verify relative tool diagnostics through MCP

Refs #7569

Co-Authored-By: gensokyo-dev <342580529+gensokyo-dev@users.noreply.github.com>

tests/boundary/cli/pcapRelativeToolDiagnostic.test.ts

@@ -1,6 +1,7 @@
 import { expect } from "vitest";
 
 import { cliTest } from "../../support/cli/cliFixture.js";
+import { connectLocalToolsMcp } from "../../fixtures/localToolsMcp.js";
 
 cliTest.for([
   { setting: "REA_TSHARK_COMMAND", value: "rel/tshark" },
@@ -8,17 +9,33 @@ cliTest.for([
 ] as const)(
   "Wireshark refuses and identifies the caller's relative $setting selection",
   async ({ setting, value }, { cli }) => {
+    const environment = {
+      REA_TSHARK_COMMAND: "/nonexistent/rea-test-tshark",
+      [setting]: value,
+    };
     const result = await cli.run({
       arguments: ["inspect-pcap-client", "--format", "json"],
-      environment: {
-        REA_TSHARK_COMMAND: "/nonexistent/rea-test-tshark",
-        [setting]: value,
-      },
+      environment,
       timeoutMs: 10_000,
     });
     expect(result.exitCode, result.stderr).toBe(1);
     expect(result.stdout).toContain(setting);
     expect(result.stdout).toContain(value);
     expect(result.stdout).toContain("absolute path");
+    expect(result.json).toMatchObject({
+      code: "capability_unavailable",
+      retryable: false,
+      details: { diagnostics: { configured: value } },
+    });
+    const { client, call } = await connectLocalToolsMcp(environment);
+    try {
+      const reply = await call("inspect_pcap_client", {});
+      expect(reply.isError).toBe(true);
+      const content = reply.content.find((item) => item.type === "text");
+      if (content?.type !== "text") throw new Error("Missing MCP error text");
+      expect(JSON.parse(content.text)).toEqual({ error: result.json });
+    } finally {
+      await client.close();
+    }
   },
 );