Offline-First Merchandising Mobile App

I need a cross-platform mobile application for field merchandisers that works reliably even when there is no internet connection. The main requirement is an offline-first workflow. Field users should be able to scan product barcodes or manually enter article numbers using their Android or iOS device. The scanned information must be saved locally immediately, without requiring an internet connection. Main Requirements 1. Barcode & Article Scanning - Camera-based barcode scanning. - Manual article-number entry. - Fast scanning workflow suitable for field employees. - Item/product information should be displayed immediately. - All scans must be stored locally when offline. 2. Offline Functionality - The app must remain fully usable without network coverage. - Local database/storage should securely retain all relevant data. - Users should be able to continue scanning and printing labels while offline. - The app must prevent data loss if connectivity is interrupted. 3. Label Creation & Printing - Create and edit labels directly from the mobile app. - Generate labels based on scanned/article information. - Immediate label printing. - Support Bluetooth and/or Wi-Fi label printers, depending on the printer model. - Print jobs should be handled reliably even when the device is temporarily offline. 4. Automatic Synchronization - When internet connectivity returns, the app should automatically synchronize local data with the central server. - Background synchronization is required. - Sync should handle failed uploads/retries and avoid duplicate records. - Users should be able to see whether data is synced, pending, or failed. - Authorized colleagues should be able to see synchronized information in near real time. 5. User & Role Management I need lightweight admin functionality inside the application. Admins should be able to: - Create/edit/deactivate users. - Grant or revoke access. - Create customizable roles. - Assign permissions to individual users or roles. - Control which screens/features each employee can access. - Modify permissions as business requirements change. 6. Configuration Management - Ability to change small application configurations without requiring a separate back-office application. - Configuration changes should synchronize to users' devices. - Changes should work correctly with the offline-first architecture. Platforms & Technology The application must support: - Android - iOS I prefer a proven shared-codebase technology such as Flutter or React Native, although I am open to another suitable technology if there is a strong technical reason. The architecture should include: - Offline local database - Secure backend/API - Background sync engine - Conflict/error handling - Authentication - Role-based access control - Secure data transmission - Scalable cloud database/backend Important Priorities The most important aspects are: 1. Reliable offline operation 2. Fast barcode scanning 3. Immediate label printing 4. Reliable automatic synchronization 5. Customizable roles and permissions 6. Simple and fast UI for field employees 7. Data security and prevention of data loss The final solution should be production-ready, scalable, maintainable, and easy for field employees with limited technical knowledge to use. I would also like the developer/team to recommend the best technical architecture, local database, backend technology, synchronization strategy, and compatible label-printer approach based on the requirements.