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/health/health.controller.ts

@@ -0,0 +1,18 @@
+import { Controller, Get } from "@nestjs/common"
+import { ApiOkResponse, ApiOperation, ApiTags } from "@nestjs/swagger"
+
+import { HealthResponseDto } from "./health-response.dto"
+
+@ApiTags("system")
+@Controller("health")
+export class HealthController {
+  @Get()
+  @ApiOperation({ summary: "Проверить состояние API" })
+  @ApiOkResponse({ type: HealthResponseDto })
+  getHealth(): HealthResponseDto {
+    return {
+      service: "image-platform-api",
+      status: "ok",
+    }
+  }
+}