Updated the project version in `EnvelopeGenerator.API.csproj`
from `1.3.0` to `1.3.1`, including `<Version>`, `<FileVersion>`,
and `<AssemblyVersion>` properties, indicating a minor update.
Simplified the YARP proxy mapping in `Program.cs` by replacing
the conditional `app.MapWhen` logic with a direct call to
`app.MapReverseProxy()`, allowing all requests to be forwarded
through the reverse proxy without path filtering.
TekH
5dc32a02a9