feat: V2 microservices stack — backend services, gateway, JWT auth

Add full V2 architecture: identity, content, studio (.NET 10) and file,
render, notification, gateway (Go) services with vendored deps, plus DB
migrations, event/API contracts, and an init-db script.

Wire the Next.js frontend to the gateway: server-side JWT auth routes
(login/register/refresh/logout/me), gateway fetch helper, and session/
cookie/jwt helpers under src/lib.

Containerize the stack via docker-compose.v2.yml and per-service
Dockerfiles. Base images resolve through a Nexus mirror (Docker Hub) and
MCR directly; npm/NuGet pull from Nexus groups. Self-host fonts via
next/font/local to avoid Google Fonts (geo-blocked).

Add CI workflow and ignore .env.v2, *.stackdump, and .NET bin/obj.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

services/render/vendor/github.com/gin-gonic/gin/deprecated.go

@@ -0,0 +1,23 @@
+// Copyright 2014 Manu Martinez-Almeida. All rights reserved.
+// Use of this source code is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package gin
+
+import (
+	"log"
+
+	"github.com/gin-gonic/gin/binding"
+)
+
+// BindWith binds the passed struct pointer using the specified binding engine.
+// See the binding package.
+//
+// Deprecated: Use MustBindWith or ShouldBindWith.
+func (c *Context) BindWith(obj any, b binding.Binding) error {
+	log.Println(`BindWith(\"any, binding.Binding\") error is going to
+	be deprecated, please check issue #662 and either use MustBindWith() if you
+	want HTTP 400 to be automatically returned if any error occur, or use
+	ShouldBindWith() if you need to manage the error.`)
+	return c.MustBindWith(obj, b)
+}