Extract Ladill QR Plus as standalone app at qr.ladill.com.

Utility QR types only (URL, WiFi, link list, business, app download) with
SSO, Billing API integration, public /q resolver, and qr-plus:import for
platform migration. vCard and commerce types stay on the platform.

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

config/qr.php

@@ -0,0 +1,9 @@
+<?php
+
+return [
+    'price_per_qr_ghs' => (float) env('QR_PRICE_PER_QR_GHS', 5.0),
+    'min_topup_ghs' => (float) env('QR_MIN_TOPUP_GHS', 5.0),
+    'max_pdf_bytes' => (int) env('QR_MAX_PDF_BYTES', 104857600), // 100 MB
+    'short_code_length' => (int) env('QR_SHORT_CODE_LENGTH', 8),
+    'scan_unique_window_hours' => (int) env('QR_SCAN_UNIQUE_WINDOW_HOURS', 24),
+];