feat: add current user and tenant endpoints

Tiku.Api/Middleware/ExceptionHandlingMiddleware.cs

@@ -1,4 +1,5 @@
 using Microsoft.AspNetCore.Mvc;
+using Tiku.Application.Auth;
 
 namespace Tiku.Api.Middleware;
 
@@ -15,6 +16,12 @@ public sealed class ExceptionHandlingMiddleware(
         }
         catch (Exception exception)
         {
+            if (exception is AuthException authException)
+            {
+                await WriteAuthProblemAsync(context, authException);
+                return;
+            }
+
             logger.LogError(exception, "Unhandled API exception");
 
             var problem = new ProblemDetails
@@ -30,4 +37,26 @@ public sealed class ExceptionHandlingMiddleware(
             await context.Response.WriteAsJsonAsync(problem);
         }
     }
+
+    private static async Task WriteAuthProblemAsync(HttpContext context, AuthException exception)
+    {
+        var status = exception.Code switch
+        {
+            "tenant_access_denied" => StatusCodes.Status403Forbidden,
+            "sms_rate_limited" => StatusCodes.Status429TooManyRequests,
+            "session_revoked" => StatusCodes.Status401Unauthorized,
+            _ => StatusCodes.Status401Unauthorized
+        };
+        var problem = new ProblemDetails
+        {
+            Title = exception.Message,
+            Status = status,
+            Instance = context.Request.Path
+        };
+
+        problem.Extensions["code"] = exception.Code;
+        problem.Extensions["traceId"] = context.TraceIdentifier;
+        context.Response.StatusCode = status;
+        await context.Response.WriteAsJsonAsync(problem);
+    }
 }