Fix import related TypeScript errors (#9321)

* Add missing @types packages

* Fix TS1272 type only imports

* Fix TS2821 import assertion

packages/backend/src/server/MediaProxyServerService.ts

@@ -2,7 +2,6 @@ import * as fs from 'node:fs';
 import { fileURLToPath } from 'node:url';
 import { dirname } from 'node:path';
 import { Inject, Injectable } from '@nestjs/common';
-import { FastifyInstance, FastifyPluginOptions, FastifyReply, FastifyRequest } from 'fastify';
 import sharp from 'sharp';
 import fastifyStatic from '@fastify/static';
 import { DI } from '@/di-symbols.js';
@@ -18,6 +17,7 @@ import type Logger from '@/logger.js';
 import { FileInfoService } from '@/core/FileInfoService.js';
 import { LoggerService } from '@/core/LoggerService.js';
 import { bindThis } from '@/decorators.js';
+import type { FastifyInstance, FastifyPluginOptions, FastifyReply, FastifyRequest } from 'fastify';
 
 const _filename = fileURLToPath(import.meta.url);
 const _dirname = dirname(_filename);