Codespaces ResourceBuilder.GetEndpoint("https") always returns localhost instead of the Codespaces domain name.

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Describe the bug

Codespaces ResourceBuilder.GetEndpoint("https") always returns localhost instead of the Codespaces domain name.

### Expected Behavior

_No response_

### Steps To Reproduce

_No response_

### Exceptions (if any)

_No response_

### Aspire doctor output

_No response_

### Anything else?

_No response_

Start by locating the C# implementation of ResourceBuilder.GetEndpoint and inspect how the "https" endpoint is resolved in Codespaces. Reproduce or trace the current result, then verify that the endpoint uses the Codespaces domain name instead of localhost.

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