feat: initialize mini api skeleton

src/Modules/TakeoutSaaS.Module.Tenancy/NoOpTenantCodeResolver.cs

@@ -0,0 +1,15 @@
+namespace TakeoutSaaS.Module.Tenancy;
+
+/// <summary>
+/// 默认空实现，不做数据库或远程租户解析。
+/// </summary>
+public sealed class NoOpTenantCodeResolver : ITenantCodeResolver
+{
+    /// <inheritdoc />
+    public Task<long?> ResolveAsync(string code, CancellationToken cancellationToken = default)
+    {
+        _ = code;
+        _ = cancellationToken;
+        return Task.FromResult<long?>(null);
+    }
+}