fix: save llm key without extra secret

admin-web/src/views/ModelService.vue

@@ -201,7 +201,7 @@ function sourceLabel(source: ApiKeyState['source']) {
               <a-button danger :loading="deletingKey">删除</a-button>
             </a-popconfirm>
           </div>
-          <p class="key-note">服务端需配置 <code>Secrets__EncryptionKey</code> 才能加密保存，值为 Base64 编码的 32 字节密钥。</p>
+          <p class="key-note">保存时由服务端自动加密，不需要额外配置加密密钥。</p>
         </template>
         <a-alert v-else type="info" message="只有超级管理员可以替换或删除 API Key。" show-icon />
       </section>
@@ -234,7 +234,6 @@ function sourceLabel(source: ApiKeyState['source']) {
 .key-status strong { font-variant-numeric: tabular-nums; letter-spacing: .04em; }
 .key-editor { display: grid; grid-template-columns: minmax(240px, 1fr) auto auto; gap: 10px; }
 .key-note { margin: 10px 0 0; color: #5e6772; font-size: 12px; }
-.key-note code { color: #414eb8; }
 .result-alert { margin-bottom: 18px; }
 @media (max-width: 760px) {
   .page-heading { flex-direction: column; }