test: warn on shared agent dirs

src/config/config.multi-agent-agentdir-validation.test.ts

@@ -18,8 +18,19 @@ describe("multi-agent agentDir validation", () => {
     });
     expect(res.ok).toBe(false);
     if (!res.ok) {
-      expect(res.issues.map((issue) => issue.path)).toContain("agents.list");
-      expect(res.issues[0]?.message).toContain("Duplicate agentDir");
+      expect(res.issues).toEqual([
+        {
+          path: "agents.list",
+          message: `Duplicate agentDir detected (multi-agent config).
+Each agent must have a unique agentDir; sharing it causes auth/session state collisions and token invalidation.
+
+Conflicts:
+- ${shared}: "a", "b"
+
+Fix: remove the shared agents.list[].agentDir override (or give each agent its own directory).
+If you want to share credentials, copy auth-profiles.json instead of sharing the entire agentDir.`,
+        },
+      ]);
     }
   });