feat(utils): add utility to mask API keys

- Introduces a function to mask API keys for improved security
- Masks null or short keys entirely with asterisks
- Partially masks longer keys, retaining the first five characters

src/utils.ts

@@ -0,0 +1,6 @@
+export const maskApiKey = (key: string | null): string => {
+    if (!key) return '*****';
+    return key.length <= 5
+        ? '*'.repeat(key.length)
+        : key.slice(0, 5) + '*'.repeat(key.length - 5);
+};