Implement comprehensive free trial system

### Overview
Added complete trial functionality to subscription system with instant activation, admin management, and user access control integration

### Key Changes
- [Add detailed changes here]

### Technical Implementation
- [Add technical details here]

### Impact
- [Add impact assessment here]

### Gambaran Umum
[Indonesian translation of description]

### Perubahan Utama
- [Tambahkan perubahan detail di sini]

### Implementasi Teknis
- [Tambahkan detail teknis di sini]

### Dampak
- [Tambahkan penilaian dampak di sini]