Missing dedicated privilege for accessing REST API documentation #961

Describe the bug

The REST API documentation page (/api/v2/documentation) does not have a dedicated privilege available in pfSense's Assigned Privileges list.

Currently, granting access to this page appears to require the WebCfg - All pages (page-all) privilege, which provides significantly broader permissions than necessary.

This prevents administrators from allowing restricted users to access the API documentation without granting excessive permissions.

To Reproduce

1. Go to System > User Manager.
2. Create or edit a non-administrative user or group.
3. Open Assigned Privileges and click Add.
4. Search for a privilege related to REST API documentation.
5. Notice that no dedicated privilege is available.
6. Attempt to grant access to /api/v2/documentation without assigning WebCfg - All pages.

Expected behavior

A dedicated privilege, such as WebCfg - REST API Documentation, should be available under Assigned Privileges.

This would allow administrators to grant access to the Swagger/OpenAPI documentation independently of other WebGUI pages.

Access to individual API endpoints should continue to be governed by their existing permissions.

Screenshots or Response

N/A

pfSense Version & Package Version

• pfSense Version: 2.9.0
• Package Version: v2.10.2

Affected Endpoints

• URL: /api/v2/documentation

Additional context

This is particularly relevant when configuring limited-access users that need to consult the API swagger documentation while following the principle of least privilege.

Ideally, the package should register this privilege automatically during installation, making it available through the standard pfSense privilege management interface.