Adds ForwardedHeaders and debug endpoint

Adds ForwardedHeaders to handle reverse proxy scenarios.

Adds a debug endpoint to display the correct scheme and host
when running behind a reverse proxy, aiding in debugging
authentication issues.

Source/ProofOfConcept/Program.cs

@@ -94,6 +94,8 @@ builder.Services.AddHostedService<MQTTClient>();
 //Build app
 WebApplication app = builder.Build();
 
+app.UseForwardedHeaders();
+
 if (app.Environment.IsDevelopment())
 {
     app.MapOpenApi();
@@ -133,6 +135,13 @@ if (app.Environment.IsDevelopment())
             ExpiresAtRaw = expiresAtRaw
         });
     });
+    app.MapGet("DebugProxy", (IHttpContextAccessor httpContextAccessor) =>
+    {
+        var ctx = httpContextAccessor.HttpContext!;
+        var request = ctx.Request;
+
+        return $"{request.Scheme}://{request.Host}/token-exchange";
+    });
 }
 
 //Map static assets