feat(api): add BNPL, ERP, WhatsApp Cloud, Supplier Portal stubs

- bnpl_bp.py: APLAZO/Kueski/Clip application workflow (mock)
- erp_bp.py: Aspel/CONTPAQi/SAP/Odoo sync jobs (mock)
- whatsapp_cloud_bp.py: Meta Cloud API webhook, messages, templates
- supplier_portal_bp.py: demand by zone/branch and top-parts analytics
- app.py: register all new blueprints

pos/app.py

@@ -89,6 +89,21 @@ def create_app():
     from blueprints.tasks_bp import tasks_bp
     app.register_blueprint(tasks_bp)
 
+    from blueprints.bnpl_bp import bnpl_bp
+    app.register_blueprint(bnpl_bp)
+
+    from blueprints.erp_bp import erp_bp
+    app.register_blueprint(erp_bp)
+
+    from blueprints.whatsapp_cloud_bp import whatsapp_cloud_bp
+    app.register_blueprint(whatsapp_cloud_bp)
+
+    from blueprints.dashboard_stats_bp import dashboard_stats_bp
+    app.register_blueprint(dashboard_stats_bp)
+
+    from blueprints.supplier_portal_bp import supplier_portal_bp
+    app.register_blueprint(supplier_portal_bp)
+
     # Health check
     @app.route('/pos/health')
     def health():