test lang_code and filename mismatch (#1441)

## Description:

Ensure that each lang_code matches its corresponding filename in
language JSON files.

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

tests/LangCode.test.ts

@@ -0,0 +1,27 @@
+import fs from "fs";
+import path from "path";
+
+describe("LangCode Filename Check", () => {
+  const langDir = path.join(__dirname, "../resources/lang");
+
+  test("lang_code matches filename", () => {
+    const files = fs
+      .readdirSync(langDir)
+      .filter((file) => file.endsWith(".json"));
+
+    if (files.length === 0) {
+      console.log("No resources/lang/*.json files found. Skipping check.");
+      return;
+    }
+
+    for (const file of files) {
+      const filePath = path.join(langDir, file);
+      const jsonData = JSON.parse(fs.readFileSync(filePath, "utf-8"));
+
+      const fileNameWithoutExt = path.basename(file, ".json");
+      const langCode = jsonData.lang?.lang_code;
+
+      expect(fileNameWithoutExt).toBe(langCode);
+    }
+  });
+});