feat(个人主页): 后端一个接口给齐主页要的东西：做对的题带题名和日期、四个时间、本班第几、成就，老师和本人多拿知识点和没做对的题

- GET /profiles/:username/overview：同学看拿不到知识点和没做对的题，多一份「你和他」
- DELETE /me/avatar：不用图片，退回名字的字
- 知识点地图抽成 knowledgeMapOf，老师看学生也能用
- 删掉没人用了的 /users/:id/metrics

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/web/src/oj/user/setting.vue

@@ -1,88 +0,0 @@
-<script setup lang="ts">
-import { MOOD_MAX } from "@oj2/contract"
-import { updateProfile, uploadAvatar } from "oj/api"
-import { useUserStore } from "shared/store/user"
-
-const userStore = useUserStore()
-const message = useMessage()
-
-async function beforeUpload(data: { file: UploadFileInfo; fileList: UploadFileInfo[] }) {
-  if (!data.file.file) return false
-  if (data.file.file.size > 2 * 1024 * 1024) {
-    message.warning("图片太大啦！不能超过 2 MB 啊")
-    return false
-  }
-  return true
-}
-
-async function upload({ file }: UploadCustomRequestOptions) {
-  try {
-    await uploadAvatar(file.file!)
-    message.success("上传成功")
-    userStore.getMyProfile()
-  } catch (err) {
-    message.error("上传失败")
-  }
-}
-
-async function saveProfile() {
-  // 以前限 256 字，老的长签名还在库里：输入框挡不住已有的字，存之前先说清楚
-  const length = userStore.profile?.mood?.trim().length ?? 0
-  if (length > MOOD_MAX) {
-    message.warning(`个性签名最多 ${MOOD_MAX} 个字，现在有 ${length} 个，删短一点再保存`)
-    return
-  }
-  try {
-    await updateProfile({
-      realName: userStore.profile?.realName ?? "",
-      mood: userStore.profile?.mood ?? "",
-    })
-    message.success("更改成功")
-  } catch (err) {
-    message.error("更改失败")
-  }
-}
-</script>
-<template>
-  <n-flex class="container" vertical v-if="userStore.profile">
-    <h2>个人信息设置</h2>
-    <n-form>
-      <n-avatar round :size="120" :src="userStore.profile.avatar" alt="头像" />
-      <n-form-item label="">
-        <n-upload
-          :show-file-list="false"
-          accept="image/*"
-          @before-upload="beforeUpload"
-          :custom-request="upload"
-        >
-          <n-button>上传头像</n-button>
-        </n-upload>
-      </n-form-item>
-      <!-- <n-form-item label="真名">
-        <n-input v-model:value="userStore.profile.realName" />
-      </n-form-item> -->
-      <n-form-item label="个性签名">
-        <n-input
-          v-model:value="userStore.profile.mood"
-          :maxlength="MOOD_MAX"
-          show-count
-          placeholder="会显示在排名和个人主页上"
-        />
-      </n-form-item>
-      <n-button @click="saveProfile">更改信息</n-button>
-    </n-form>
-  </n-flex>
-</template>
-<style scoped>
-.container {
-  max-width: 640px;
-  margin: 0 auto;
-  padding-top: 8px;
-  gap: var(--oj-gap);
-}
-
-h2 {
-  margin: 0;
-  font-size: var(--oj-fs-title);
-}
-</style>