PolarisPrincipal missing user-defined attributes supplied during principal creation

### Describe the bug

When an API request is authenticated using a user principal, the internally constructed PolarisPrincipal object contains only internal attributes (such as client_id) and does not include the user-defined attributes that were supplied during principal creation.

### To Reproduce

1. Create a principal using the API:
POST /api/management/v1/principals

Include user-defined attributes, for example:
region=northamerica
department=finance

2. Use the returned client-id and client-secret to obtain an OAuth token:
POST /api/catalog/v1/oauth/tokens

3. Use the generated OAuth token to invoke an authenticated API (for example):
GET /api/management/v1/catalogs

4. Inspect the server-side PolarisPrincipal object created during request processing.

### Actual Behavior

The PolarisPrincipal object contains only internal attributes (for example, client_id) and does not include user-defined attributes that were supplied during principal creation.

### Expected Behavior

The PolarisPrincipal object should include both:
* Internal attributes (such as client_id), and
* User-defined attributes supplied during principal creation.

### Additional context

Based on initial debugging, it appears that when PolarisPrincipal is created from PrincipalEntity, the implementation uses:

principalEntity.getInternalPropertiesAsMap()

This retains internal attributes but excludes user-defined properties.

Using:
principalEntity.getPropertiesAsMap() along with principalEntity.getInternalPropertiesAsMap() will preserve both internal and user-defined attributes.

### System information

_No response_

Locate where PolarisPrincipal is created from PrincipalEntity and inspect the attribute maps used there. Verify the behavior with a focused test or existing authentication flow, and consider the issue done when the resulting principal retains both internal and user-defined attributes.

Written by the indexing model from the issue text.