P0: Standardize API response envelope

[Kinin-Code-Offical]

API responses are inconsistent. All endpoints must return a standardized JSON object.

Acceptance Criteria:

• All API endpoints MUST return a JSON object with the structure: { success: bool, message: string, data: object|array|null }.
• For list responses, the data object should contain an items array: data: { items: [...] }.
• Refactor at least two key endpoints (e.g., getallclients.php, getallpolicies.php) to use the new envelope.

[Kinin-Code-Offical]

This is an automated message from the full-stack agent.

Execution Plan for Issue #82:

1. Analyze: I will read �ackend/clients/getallclients.php and �ackend/policies/getallpolicies.php to verify their current JSON response structures against the standard envelope: { success, message, data }.
2. Implement: If the endpoints are not compliant, I will refactor them.
   • On success, the response will be { success: true, message: 'Data retrieved successfully.', data: { items: [...] } }.
   • On failure, they will return { success: false, message: 'An error occurred.', data: null }.
   • I will also ensure they are using the modern JWT-based authentication.
3. Verification & PR: If changes are made, I will create a new branch and open a Pull Request. If the files are already compliant, I will close this issue with a note.

I will now proceed with the analysis.