接入 ESLint 并清理未使用代码

- 前后端接入 ESLint 10 扁平配置（typescript-eslint 类型感知检查 + react-hooks/react-refresh），新增 lint / lint:check / lint:fix 脚本并纳入 check 链路
- 清理全部 no-unused-vars 与 no-useless-assignment 警告，修复 floating promises、正则转义等问题
- 删除确认无引用的死代码（markKuaishouCloudBindUrlRefreshFailed、未使用 helper 等）

apps/frontend/src/components/DeadlineCountdown.tsx

@@ -3,7 +3,7 @@ import { useEffect, useState } from 'react'
 
 export function DeadlineCountdown({
   deadlineAt,
-  showExpired = false,
+  showExpired: _showExpired = false,
 }: {
   deadlineAt: string
   showExpired?: boolean

apps/frontend/src/components/files/ImageUpload.tsx

@@ -169,15 +169,17 @@ export default function ImageUpload({
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [captureGlobalPaste])
 
-  function handleWrapperFocus(event: FocusEvent<HTMLDivElement>) {
+  function handleWrapperFocus(_event: FocusEvent<HTMLDivElement>) {
     if (captureGlobalPaste) activateGlobalPasteTarget()
   }
 
-  function handleWrapperClick(event: MouseEvent<HTMLDivElement>) {
+  function handleWrapperClick(_event: MouseEvent<HTMLDivElement>) {
     if (captureGlobalPaste) activateGlobalPasteTarget()
   }
 
-  const customRequest: UploadProps['customRequest'] = async (options) => {
+  async function uploadFromRequest(
+    options: Parameters<NonNullable<UploadProps['customRequest']>>[0],
+  ) {
     try {
       const uploaded = await uploadFile(options.file as File, scene, scope)
       // 多文件选择会并发执行 customRequest，必须以 ref 中的最新列表累加，避免后完成的上传覆盖前面的图片。
@@ -191,6 +193,10 @@ export default function ImageUpload({
     }
   }
 
+  const customRequest: UploadProps['customRequest'] = (options) => {
+    void uploadFromRequest(options)
+  }
+
   return (
     <div
       className={`image-upload-droppable ${isDragging ? 'is-dragging' : ''}`}