[Feature Request]: Agent Stock and Inventory Management

### Preflight Checklist

- [x] I have read the [Contributing Guidelines](https://github.com/EnAccess/micropowermanager/blob/main/CONTRIBUTING.md) for this project, if it exists.
- [x] I agree to follow the [Code of Conduct](https://github.com/EnAccess/micropowermanager/blob/main/CODE_OF_CONDUCT.md) that this project adheres to.
- [x] I have searched the [issue tracker](https://github.com/EnAccess/micropowermanager/issues) for a feature request that matches the one I want to file, without success.

### Problem Description

Please add Agent Inventory Management that allows users to understand which Agent has access to which stock.

Add a complete inventory management module that allows you to:

- Register the entry and exit of solar kits;
- Control inventory by agent or region;
- Automatic low stock alerts;
- GPS data collection at the time of sale; Transfer a customer from a departing agent to a new one.

Automatic or manual customer transfer:

- In case an agent leaves the company, all associated customers must be able to be transferred automatically (in batch) or manually to a new responsible agent.

- Supervisor/manager approval: Every transfer must be validated by a supervisor or manager to ensure control and prevent errors or abuse.

- Maintenance of complete customer history: The history of payments, interactions, and contracts must be fully preserved after the transfer, without data loss.
- Transfer history log (audit): The system must save: Previous agent, New agent, Transfer date, Reason (e.g., leaving the company).

### Proposed Solution

x

### Alternatives Considered

x

### Additional Information

x