[Feature]: Add per-user storage quota to prevent storage abuse and uncontrolled uploads

[DenizAltunkapan]

Problem

Currently, users are manually created in the user table. A corresponding entry should also be created for each user that defines the maximum allowed storage capacity (in MB) for their Cloud Page storage.

When a user uploads a file, the backend should verify whether the new file would exceed the user’s storage quota. If the limit would be exceeded:

• The upload must be rejected
• The API should return an appropriate error status code
• The response should inform the user that their storage limit has been reached and that they must free up space before uploading additional files

Example response message:

"Upload rejected: storage limit of (X MB) reached. Please delete files to free space."

This feature helps to:

• Prevent storage abuse and potential DDoS-style upload attacks
• Enforce per-user storage limits
• Improve overall resource management for the Cloud Page service.