feat: add catalog readonly endpoints

Tiku.Api/Middleware/ExceptionHandlingMiddleware.cs

@@ -1,4 +1,5 @@
 using Microsoft.AspNetCore.Mvc;
+using Tiku.Api.Controllers;
 using Tiku.Application.Auth;
 
 namespace Tiku.Api.Middleware;
@@ -22,6 +23,16 @@ public sealed class ExceptionHandlingMiddleware(
                 return;
             }
 
+            if (exception is TenantNotFoundException)
+            {
+                await WriteProblemAsync(
+                    context,
+                    "Tenant was not found.",
+                    StatusCodes.Status404NotFound,
+                    "tenant_not_found");
+                return;
+            }
+
             logger.LogError(exception, "Unhandled API exception");
 
             var problem = new ProblemDetails
@@ -38,6 +49,25 @@ public sealed class ExceptionHandlingMiddleware(
         }
     }
 
+    private static async Task WriteProblemAsync(
+        HttpContext context,
+        string title,
+        int status,
+        string code)
+    {
+        var problem = new ProblemDetails
+        {
+            Title = title,
+            Status = status,
+            Instance = context.Request.Path
+        };
+
+        problem.Extensions["code"] = code;
+        problem.Extensions["traceId"] = context.TraceIdentifier;
+        context.Response.StatusCode = status;
+        await context.Response.WriteAsJsonAsync(problem);
+    }
+
     private static async Task WriteAuthProblemAsync(HttpContext context, AuthException exception)
     {
         var status = exception.Code switch