Fix Mini fork leftovers in POS config

After an auto-logout, silent re-auth fails with login_required and
SsoLoginController@callback redirects to config('ladill.marketing_url') — which
still defaulted to https://ladill.com/products/mini, dumping POS users on Mini's
product page. Point ladill.product_slug/marketing_url at POS.

Also fix the identity service key (config/identity.php + services.ladill_identity
read IDENTITY_API_KEY_MINI; POS provisions IDENTITY_API_KEY_POS) and tidy the
remaining Mini defaults (app.name, ladill_sso redirect, mobile-topbar app_name).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

config/services.php

@@ -23,7 +23,7 @@ return [
         'issuer' => 'https://'.config('app.auth_domain'),
         'client_id' => env('LADILL_SSO_CLIENT_ID'),
         'client_secret' => env('LADILL_SSO_CLIENT_SECRET'),
-        'redirect' => rtrim((string) env('APP_URL', 'https://mini.ladill.com'), '/').'/sso/callback',
+        'redirect' => rtrim((string) env('APP_URL', 'https://pos.ladill.com'), '/').'/sso/callback',
     ],
 
     // Central Ladill identity API (auth.ladill.com /api/identity/auth/*). The
@@ -31,7 +31,7 @@ return [
     // shared first-party service key (config/identity.php on the monolith).
     'ladill_identity' => [
         'url' => 'https://'.config('app.auth_domain'),
-        'key' => env('IDENTITY_API_KEY_MINI'),
+        'key' => env('IDENTITY_API_KEY_POS'),
     ],
 
     'ladill_webmail' => [