Phase 007: migrate every remaining view from naive-ui to Arco Design Vue

The project now has exactly one UI library. Every naive-ui component in
packages/client/src is replaced by its Arco equivalent across 24 views and
roughly 80 components, and naive-ui is dropped from package.json along with
its transitive vueuc / @css-render / vdirs / seemly dependencies.

The migration is rendering-layer only. No store logic, no API contract, and
no /chat-run payload was touched.

Three classes of leftover were invisible to `grep naive-ui` and are now
covered by tests/client/no-naive-ui.test.ts, which asserts all three:
  - dead .n-* class names in style blocks
  - dead --n-* custom properties
  - naive-ui in package.json

Notable behavioural traps handled along the way, recorded in
docs/arco-migration-rules.md:
  - a-input-password defaults to masked; passing default-visibility="false"
    would have exposed API keys in clear text
  - a-upload fires a real XHR unless auto-upload is false
  - nested Trigger components fight over the first element child, so the
    group-chat settings dropdown was flattened
  - Arco renders tooltip default-slot text inline, which was silently
    collapsing the chat and group-chat toolbars

packages/client/src/components/hermes/models/NousLoginModal.vue

@@ -1,6 +1,5 @@
 <script setup lang="ts">
 import { ref, onUnmounted } from 'vue'
-import { NModal, NButton, NSpin } from 'naive-ui'
 import { useMessage } from '@/composables/useMessage'
 import { useI18n } from 'vue-i18n'
 import { startNousLogin, pollNousLogin } from '@/api/hermes/nous-auth'
@@ -117,18 +116,17 @@ startLogin()
 </script>
 
 <template>
-  <NModal
-    v-model:show="showModal"
-    preset="card"
+  <a-modal
+    v-model:visible="showModal"
     :title="t('models.nousLoginTitle')"
-    :style="{ width: 'min(440px, calc(100vw - 32px))' }"
+    width="min(440px, calc(100vw - 32px))"
     :mask-closable="status !== 'waiting'"
-    @after-leave="emit('close')"
+    @close="emit('close')"
   >
     <div class="nous-login">
       <!-- Idle / Loading -->
       <div v-if="status === 'idle' || status === 'loading'" class="nous-login__state">
-        <NSpin size="small" />
+        <a-spin />
       </div>
 
       <!-- Waiting for authorization -->
@@ -138,12 +136,12 @@ startLogin()
           <span class="nous-login__code-text">{{ userCode }}</span>
           <svg width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><rect x="9" y="9" width="13" height="13" rx="2"/><path d="M5 15H4a2 2 0 01-2-2V4a2 2 0 012-2h9a2 2 0 012 2v1"/></svg>
         </div>
-        <NButton type="primary" block @click="openLink">
+        <a-button type="primary" long @click="openLink">
           <template #icon>
             <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M18 13v6a2 2 0 01-2 2H5a2 2 0 01-2-2V8a2 2 0 012-2h6"/><polyline points="15 3 21 3 21 9"/><line x1="10" y1="14" x2="21" y2="3"/></svg>
           </template>
           {{ t('models.nousOpenLink') }}
-        </NButton>
+        </a-button>
       </div>
 
       <!-- Approved -->
@@ -155,22 +153,22 @@ startLogin()
       <!-- Expired -->
       <div v-else-if="status === 'expired'" class="nous-login__state">
         <p class="nous-login__error">{{ t('models.nousExpired') }}</p>
-        <NButton size="small" @click="retry">{{ t('common.retry') }}</NButton>
+        <a-button size="small" @click="retry">{{ t('common.retry') }}</a-button>
       </div>
 
       <!-- Error -->
       <div v-else-if="status === 'error'" class="nous-login__state">
         <p class="nous-login__error">{{ errorMessage }}</p>
-        <NButton size="small" @click="retry">{{ t('common.retry') }}</NButton>
+        <a-button size="small" @click="retry">{{ t('common.retry') }}</a-button>
       </div>
     </div>
 
     <template #footer>
       <div class="modal-footer">
-        <NButton :disabled="status === 'waiting'" @click="handleClose">{{ t('common.cancel') }}</NButton>
+        <a-button :disabled="status === 'waiting'" @click="handleClose">{{ t('common.cancel') }}</a-button>
       </div>
     </template>
-  </NModal>
+  </a-modal>
 </template>
 
 <style scoped lang="scss">
@@ -193,7 +191,7 @@ startLogin()
 
 .nous-login__hint {
   font-size: 14px;
-  color: var(--n-text-color, inherit);
+  color: var(--color-text-2, inherit);
   text-align: center;
   line-height: 1.6;
 }
@@ -203,14 +201,14 @@ startLogin()
   align-items: center;
   gap: 12px;
   padding: 12px 20px;
-  border: 1px solid var(--n-border-color, #e0e0e6);
+  border: 1px solid var(--color-border-2, #e0e0e6);
   border-radius: 8px;
   cursor: pointer;
   transition: border-color 0.2s;
-  background: var(--n-color, #fafafa);
+  background: var(--color-fill-2, #fafafa);
 
   &:hover {
-    border-color: var(--n-primary-color, #18a058);
+    border-color: var(--arcoblue-6, #165dff);
   }
 }
 
@@ -219,7 +217,7 @@ startLogin()
   font-weight: 700;
   font-family: monospace;
   letter-spacing: 4px;
-  color: var(--n-text-color, inherit);
+  color: var(--color-text-1, inherit);
 }
 
 .nous-login__state--success {