Update all dependencies to latest compatible versions

Major upgrades:
- axios: ^0.21.1 → ^1.13.5 (fixes known CVEs)
- lru-cache: ^5.1.1 → ^11.2.6 (maxAge→ttl, LRUCache named export)
- typescript: ^4.6.3 → ^5.9.3 (target es5→es2015)
- tslib: ^1.10.0 → ^2.8.1
- prettier: ^1.18.2 → ^3.8.1
- @typescript-eslint/*: ^2.6.1 → ^8.56.0
- eslint: ^6.5.1 → ^8.57.0
- jest: ^24.9.0 → ^29.7.0, ts-jest: ^24.1.0 → ^29.4.6

Held back ESM-only packages (is-ip, url-join) and eslint 9+
(flat config migration out of scope).

Updated CacheConfig interface (maxAge→ttl), eslint config
(removed deprecated prettier/@typescript-eslint), tsconfig
(es2015 target, explicit moduleResolution), and README.

https://claude.ai/code/session_01UabaLo3R3sXovyxaZo2yCF

Author: claude

.eslintrc.js

@@ -9,10 +9,9 @@ module.exports = {
   extends: [
     'airbnb-base',
     'plugin:@typescript-eslint/recommended',
-    'prettier/@typescript-eslint',
-    'plugin:prettier/recommended',
     'plugin:import/recommended',
-    'plugin:import/typescript'
+    'plugin:import/typescript',
+    'plugin:prettier/recommended'
   ],
   parser: '@typescript-eslint/parser',
   parserOptions: {

README.md

@@ -50,16 +50,16 @@ The library will cache 4096 ip addresses responses for 24 hours using a LRU cach
 ```js
 const cacheConfig = {
   max: 1000, // max size
-  maxAge: 10 * 60 * 1000, // max age in ms (i.e. 10 minutes)
+  ttl: 10 * 60 * 1000, // time-to-live in ms (i.e. 10 minutes)
 };
 const ipdata = new IPData('<apiKey>', cacheConfig);
 ```
 
-**Note:** To disable the cache pass `-1` as the `maxAge`.
+**Note:** To disable the cache pass `1` as the `ttl` (1ms effectively disables caching).
 
 ```js
 const cacheConfig = {
-  maxAge: -1, // disable the cache
+  ttl: 1, // disable the cache
 };
 const ipdata = new IPData('<apiKey>', cacheConfig);
 ```