Add GeoIP country fallback for link click analytics.

Resolve countries from CDN headers first, then MaxMind GeoLite2 via visitor IP, with an artisan command to download and refresh the database.

Co-authored-by: Cursor <cursoragent@cursor.com>

config/link.php

@@ -5,4 +5,7 @@ return [
     'slug_length' => (int) env('LINK_SLUG_LENGTH', 8),
     'click_unique_window_hours' => (int) env('LINK_CLICK_UNIQUE_WINDOW_HOURS', 24),
     'public_domain' => env('LINK_PUBLIC_DOMAIN', 'ladl.link'),
+    'geoip_database' => env('LINK_GEOIP_DATABASE', storage_path('app/geoip/GeoLite2-Country.mmdb')),
+    'maxmind_account_id' => env('MAXMIND_ACCOUNT_ID'),
+    'maxmind_license_key' => env('MAXMIND_LICENSE_KEY'),
 ];