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/graphql/resolvers/models.ts

@@ -0,0 +1,63 @@
+import { builder } from "../builder.js";
+import { ModelType } from "../types/index.js";
+import { users, user_photos, files } from "../../db/schema/index.js";
+import { eq, and, desc } from "drizzle-orm";
+
+async function enrichModel(db: any, user: any) {
+  // Fetch photos
+  const photoRows = await db
+    .select({ id: files.id, filename: files.filename })
+    .from(user_photos)
+    .leftJoin(files, eq(user_photos.file_id, files.id))
+    .where(eq(user_photos.user_id, user.id))
+    .orderBy(user_photos.sort);
+
+  return {
+    ...user,
+    photos: photoRows.map((p: any) => ({ id: p.id, filename: p.filename })),
+  };
+}
+
+builder.queryField("models", (t) =>
+  t.field({
+    type: [ModelType],
+    args: {
+      featured: t.arg.boolean(),
+      limit: t.arg.int(),
+    },
+    resolve: async (_root, args, ctx) => {
+      let query = ctx.db
+        .select()
+        .from(users)
+        .where(eq(users.role, "model"))
+        .orderBy(desc(users.date_created));
+
+      if (args.limit) {
+        query = (query as any).limit(args.limit);
+      }
+
+      const modelList = await query;
+      return Promise.all(modelList.map((m: any) => enrichModel(ctx.db, m)));
+    },
+  }),
+);
+
+builder.queryField("model", (t) =>
+  t.field({
+    type: ModelType,
+    nullable: true,
+    args: {
+      slug: t.arg.string({ required: true }),
+    },
+    resolve: async (_root, args, ctx) => {
+      const model = await ctx.db
+        .select()
+        .from(users)
+        .where(and(eq(users.slug, args.slug), eq(users.role, "model")))
+        .limit(1);
+
+      if (!model[0]) return null;
+      return enrichModel(ctx.db, model[0]);
+    },
+  }),
+);