refactor: 移除废弃的 Context 类型并优化类型定义

- 移除 Context 类型导入并添加空对象类型定义以兼容当前上下文需求
- 移除已废弃的 Context 类型定义并清理注释代码

apps/server/src/api/server.ts

@@ -1,5 +1,7 @@
 import { implement } from '@orpc/server'
 import { contract } from './contract'
-import type { Context } from './types'
+
+// biome-ignore lint/complexity/noBannedTypes: 暂无 context
+type Context = {}
 
 export const os = implement(contract).$context<Context>()

apps/server/src/api/types.ts

@@ -5,8 +5,6 @@ import type {
 } from '@orpc/contract'
 import type { contract } from './contract'
 
-// biome-ignore lint/complexity/noBannedTypes: 暂无 context
-export type Context = {}
 export type Contract = typeof contract
 export type RouterClient = ContractRouterClient<Contract>
 export type RouterInputs = InferContractRouterInputs<Contract>