feat: добавить базовые сервисы image-platform

- добавлены backend, admin, gateway и worker skeleton
- добавлены Drizzle schema, database package и initial migration
- добавлены shared packages для RabbitMQ topology и S3 helpers
- обновлены dev-инфраструктура, env example, scripts и dependencies
- обновлена документация под versioned image URLs и read-through flow

apps/backend/src/internal-images/ensure-image-variant.dto.ts

@@ -0,0 +1,21 @@
+import { ApiProperty } from "@nestjs/swagger"
+
+export class EnsureImageVariantRequestDto {
+  @ApiProperty({ example: "asset_123" })
+  assetId!: string
+
+  @ApiProperty({ example: 4, minimum: 1 })
+  version!: number
+
+  @ApiProperty({ example: "card" })
+  preset!: string
+
+  @ApiProperty({ example: 640, minimum: 1 })
+  width!: number
+
+  @ApiProperty({ example: 80, minimum: 1 })
+  quality!: number
+
+  @ApiProperty({ enum: ["auto", "avif", "webp", "jpg", "png"], example: "auto" })
+  format!: "auto" | "avif" | "jpg" | "png" | "webp"
+}