chore: add tests for schema and API config mocking

- Added unit tests for schema loader, mocking Config variables and resolvers.
- Added unit tests for Zabbix API configuration, verifying constants derived from Config.
- Mocked relevant modules and filesystem behaviors to enable isolated testing.
- Optimized imports on all files and include this within a new .junie/guidelines.md file

src/test/zabbix_api_config.test.ts

@@ -0,0 +1,19 @@
+// Import after mocking Config
+import {ZABBIX_EDGE_DEVICE_BASE_GROUP, zabbixAPI, zabbixSuperAuthToken} from "../datasources/zabbix-api.js";
+
+// Mocking Config
+jest.mock("../common_utils.js", () => ({
+    Config: {
+        ZABBIX_EDGE_DEVICE_BASE_GROUP: "CustomEdgeGroup",
+        ZABBIX_AUTH_TOKEN: "super-secret-token",
+        ZABBIX_BASE_URL: "http://custom-zabbix"
+    }
+}));
+
+describe("Zabbix API Config Mocking", () => {
+    test("constants are derived from Config", () => {
+        expect(ZABBIX_EDGE_DEVICE_BASE_GROUP).toBe("CustomEdgeGroup");
+        expect(zabbixSuperAuthToken).toBe("super-secret-token");
+        expect(zabbixAPI.baseURL).toBe("http://custom-zabbix");
+    });
+});