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/backend/src/services/admin/admin-auth-service.ts

@@ -150,7 +150,7 @@ export async function verifyAdminSessionToken(token: unknown): Promise<AdminSess
     })
   }
 
-  let payload: JsonObject | null = null
+  let payload: JsonObject | null
 
   try {
     payload = JSON.parse(Buffer.from(encodedPayload, 'base64url').toString('utf8'))

apps/backend/src/services/admin/admin-read-service.ts

@@ -5,7 +5,7 @@ import { listOrderItemsByOrderId } from '../../repositories/order-item-repo.js'
 import { getOrderById, listOrders } from '../../repositories/order-repo.js'
 import { getTaskById, listTasks, listTasksByOrderId } from '../../repositories/task-repo.js'
 import { listTaskEventsByTaskId } from '../../repositories/task-event-repo.js'
-import type { JsonObject, JsonRecord } from '../../types/json.js'
+import type { JsonRecord } from '../../types/json.js'
 import {
   listKuaishouIndustryVouchersByOid,
   listKuaishouIndustryVouchersByTaskId,
@@ -474,7 +474,7 @@ function buildCloudSourceLabelMap() {
 
 export async function getAdminTaskScreenshotPath(
   taskId: AdminEntityIdInput,
-  session: AdminViewerSessionInput | null = null,
+  _session: AdminViewerSessionInput | null = null,
 ): Promise<string> {
   const task = await getRequiredTask(taskId)
 

apps/backend/src/services/admin/admin-read-shared-helpers.ts

@@ -1,6 +1,6 @@
 import { safeParseJson } from './admin-query-utils.js'
 import { normalizeAdminRole } from './admin-auth-service.js'
-import { asJsonObject, type JsonObject, JsonRecord } from '../../types/json.js'
+import { asJsonObject, type JsonRecord } from '../../types/json.js'
 import {
   parseTaskContext as parseTaskContextValue,
   parseTaskState as parseTaskStateValue,
@@ -379,7 +379,7 @@ export function createAdminViewerContext(
 
 export async function resolveAdminTaskScreenshotUrl(
   task: TaskLike,
-  viewerContext: AdminViewerContext,
+  _viewerContext: AdminViewerContext,
 ): Promise<string> {
   if (task.screenshot_path || task.runtime_session_id) {
     return `/api/v1/admin/tasks/${task.id}/screenshot`

apps/backend/src/services/admin/admin-task-read-helpers.ts

@@ -1,7 +1,7 @@
 import { getTaskById } from '../../repositories/task-repo.js'
 import { createHttpError } from '../../utils/http.js'
 import { safeParseJson } from './admin-query-utils.js'
-import { asJsonObject, type JsonObject, JsonRecord } from '../../types/json.js'
+import { asJsonObject, type JsonRecord } from '../../types/json.js'
 import {
   TASK_STATUS,
   isTaskFulfillmentCompletedStatus,