Fix client IP address detection to show real user IP instead of AppGateway internal IP

[tjementum]

Summary & Motivation

Fix the Sessions dialog showing the AppGateway's internal IP address (e.g., 10.0.0.54) instead of the user's real public IP address. This regression was introduced in commit c67bdac which added YARP's AddXForwarded transform.

• Remove YARP's AddXForwarded() transform from AppGateway, which was replacing the original X-Forwarded-For header set by Azure Container Apps ingress
• Update HttpExecutionContext.ClientIpAddress to read the X-Forwarded-For header directly and extract the first IP address (the original client), with a fallback to RemoteIpAddress for local development

The previous approach relied on UseForwardedHeaders middleware processing the header correctly across multiple proxy hops, but YARP's AddXForwarded transform was overwriting the header with the wrong IP before it reached the backend API.

Checklist

• I have added tests, or done manual regression tests
• I have updated the documentation, if necessary

[linear]

PP-757 IP address in session overview shows IP address of AppGateway

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
22.2% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud