remove the isometric wave from the login page

The angled slab texture came from the first prototype pass and clashed
with the flat neon treatment that replaced it. Drop the component
usage, its decor wrapper and the positioning rules.

The vendored IsometricWave directory stays — it is shared vendor code
and JourneyView may still want it.

packages/client/src/views/LoginView.vue

@@ -5,7 +5,6 @@ import { useI18n } from "vue-i18n";
 import { setApiKey, hasApiKey } from "@/api/client";
 import { fetchAuthStatus, loginWithPassword } from "@/api/auth";
 import ScrambleTitle from "@/vendor/arkscore/ScrambleTitle/index.vue";
-import IsometricWave from "@/vendor/arkscore/IsometricWave/index.vue";
 
 const { t } = useI18n();
 const router = useRouter();
@@ -86,11 +85,6 @@ function fillDefaultCredentials() {
 
 <template>
   <div class="login-view">
-    <!-- 装饰位面：只承载 ArkScope 波形，不承载信息/交互 -->
-    <div class="login-decor" aria-hidden="true">
-      <IsometricWave />
-    </div>
-
     <div class="login-card">
       <div class="login-neon-edge" aria-hidden="true"></div>
 
@@ -189,33 +183,9 @@ function fillDefaultCredentials() {
   overflow: hidden;
 }
 
-// ─── 装饰位面 ────────────────────────────────────────────────────────────
-// 只承载 ArkScope 波形，一律 pointer-events: none（基线硬规则）。
-// 不承载任何信息，也不能出现在点击密集区。
-// 刻意不加网格 / 扫描线：登录是自托管控制台的入口页，低对比纹理会干扰输入识别。
-.login-decor {
-  position: absolute;
-  inset: 0;
-  overflow: hidden;
-  pointer-events: none;
-  z-index: 0;
-}
-
-// ArkScope 等距波形，对齐原型的位置与透明度
-.login-decor :deep(.iso-wrap) {
-  position: absolute;
-  left: 50%;
-  bottom: -56px;
-  transform: translateX(-50%);
-  width: min(100%, 780px);
-  opacity: 0.42;
-  pointer-events: none;
-}
-
 // ─── 卡片 ────────────────────────────────────────────────────────────────
 .login-card {
   position: relative;
-  z-index: 2;
   width: 100%;
   max-width: 424px;
   padding: 0;