test: add tests for proxy auth header in config endpoint

- Added tests for App.tsx config endpoint to verify X-MCP-Proxy-Auth header usage
- Added tests for getMCPProxyAuthToken utility function
- Tests cover:
  - Sending correct proxy auth header when token is configured
  - Not sending header when token is empty
  - Using custom header names (for future flexibility)
  - Handling config endpoint errors gracefully
- All tests passing

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

client/src/utils/__tests__/configUtils.test.ts

@@ -0,0 +1,72 @@
+import { getMCPProxyAuthToken } from "../configUtils";
+import { DEFAULT_INSPECTOR_CONFIG } from "../../lib/constants";
+import { InspectorConfig } from "../../lib/configurationTypes";
+
+describe("configUtils", () => {
+  describe("getMCPProxyAuthToken", () => {
+    test("returns token and default header name", () => {
+      const config: InspectorConfig = {
+        ...DEFAULT_INSPECTOR_CONFIG,
+        MCP_PROXY_AUTH_TOKEN: {
+          ...DEFAULT_INSPECTOR_CONFIG.MCP_PROXY_AUTH_TOKEN,
+          value: "test-token-123",
+        },
+      };
+
+      const result = getMCPProxyAuthToken(config);
+
+      expect(result).toEqual({
+        token: "test-token-123",
+        header: "X-MCP-Proxy-Auth",
+      });
+    });
+
+    test("returns empty token when not configured", () => {
+      const config: InspectorConfig = {
+        ...DEFAULT_INSPECTOR_CONFIG,
+        MCP_PROXY_AUTH_TOKEN: {
+          ...DEFAULT_INSPECTOR_CONFIG.MCP_PROXY_AUTH_TOKEN,
+          value: "",
+        },
+      };
+
+      const result = getMCPProxyAuthToken(config);
+
+      expect(result).toEqual({
+        token: "",
+        header: "X-MCP-Proxy-Auth",
+      });
+    });
+
+    test("always returns X-MCP-Proxy-Auth as header name", () => {
+      const config: InspectorConfig = {
+        ...DEFAULT_INSPECTOR_CONFIG,
+        MCP_PROXY_AUTH_TOKEN: {
+          ...DEFAULT_INSPECTOR_CONFIG.MCP_PROXY_AUTH_TOKEN,
+          value: "any-token",
+        },
+      };
+
+      const result = getMCPProxyAuthToken(config);
+
+      expect(result.header).toBe("X-MCP-Proxy-Auth");
+    });
+
+    test("handles null/undefined value gracefully", () => {
+      const config: InspectorConfig = {
+        ...DEFAULT_INSPECTOR_CONFIG,
+        MCP_PROXY_AUTH_TOKEN: {
+          ...DEFAULT_INSPECTOR_CONFIG.MCP_PROXY_AUTH_TOKEN,
+          value: null as any,
+        },
+      };
+
+      const result = getMCPProxyAuthToken(config);
+
+      expect(result).toEqual({
+        token: null,
+        header: "X-MCP-Proxy-Auth",
+      });
+    });
+  });
+});