feat: replace Directus with custom Node.js GraphQL backend

Removes Directus 11 and replaces it with a lean, purpose-built backend:
- packages/backend/: Fastify v5 + GraphQL Yoga v5 + Pothos (code-first)
  with Drizzle ORM, Redis sessions (session_token cookie), argon2 auth,
  Nodemailer, fluent-ffmpeg, and full gamification system ported from bundle
- Frontend: @directus/sdk replaced by graphql-request v7; services.ts fully
  rewritten with identical signatures; directus.ts now re-exports from api.ts
- Cookie renamed directus_session_token → session_token
- Dev proxy target updated 8055 → 4000
- compose.yml: Directus service removed, backend service added (port 4000)
- Dockerfile.backend: new multi-stage image with ffmpeg
- Dockerfile: bundle build step and ffmpeg removed from frontend image
- data-migration.ts: one-time script to migrate all Directus/sexy_ tables

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/backend/src/index.ts

@@ -0,0 +1,87 @@
+import Fastify from "fastify";
+import fastifyCookie from "@fastify/cookie";
+import fastifyCors from "@fastify/cors";
+import fastifyMultipart from "@fastify/multipart";
+import fastifyStatic from "@fastify/static";
+import { createYoga } from "graphql-yoga";
+import path from "path";
+import { schema } from "./graphql/index.js";
+import { buildContext } from "./graphql/context.js";
+import { db } from "./db/connection.js";
+import { redis } from "./lib/auth.js";
+
+const PORT = parseInt(process.env.PORT || "4000");
+const UPLOAD_DIR = process.env.UPLOAD_DIR || "/data/uploads";
+const CORS_ORIGIN = process.env.CORS_ORIGIN || "http://localhost:3000";
+
+const fastify = Fastify({
+  logger: {
+    level: process.env.LOG_LEVEL || "info",
+  },
+});
+
+await fastify.register(fastifyCookie, {
+  secret: process.env.COOKIE_SECRET || "change-me-in-production",
+});
+
+await fastify.register(fastifyCors, {
+  origin: CORS_ORIGIN,
+  credentials: true,
+  methods: ["GET", "POST", "PUT", "PATCH", "DELETE", "OPTIONS"],
+});
+
+await fastify.register(fastifyMultipart, {
+  limits: {
+    fileSize: 5 * 1024 * 1024 * 1024, // 5 GB
+  },
+});
+
+await fastify.register(fastifyStatic, {
+  root: path.resolve(UPLOAD_DIR),
+  prefix: "/assets/",
+  decorateReply: false,
+});
+
+const yoga = createYoga({
+  schema,
+  context: buildContext,
+  graphqlEndpoint: "/graphql",
+  healthCheckEndpoint: "/health",
+  logging: {
+    debug: (...args) => fastify.log.debug(...args),
+    info: (...args) => fastify.log.info(...args),
+    warn: (...args) => fastify.log.warn(...args),
+    error: (...args) => fastify.log.error(...args),
+  },
+});
+
+fastify.route({
+  url: "/graphql",
+  method: ["GET", "POST", "OPTIONS"],
+  handler: async (request, reply) => {
+    const response = await yoga.handleNodeRequestAndResponse(request, reply, {
+      request,
+      reply,
+      db,
+      redis,
+    });
+    reply.status(response.status);
+    for (const [key, value] of response.headers.entries()) {
+      reply.header(key, value);
+    }
+    return reply.send(response.body);
+  },
+});
+
+fastify.get("/health", async (_request, reply) => {
+  return reply.send({ status: "ok", timestamp: new Date().toISOString() });
+});
+
+try {
+  await fastify.listen({ port: PORT, host: "0.0.0.0" });
+  fastify.log.info(`Backend running at http://0.0.0.0:${PORT}`);
+  fastify.log.info(`GraphQL at http://0.0.0.0:${PORT}/graphql`);
+} catch (err) {
+  fastify.log.error(err);
+  process.exit(1);
+}