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

vite.config.ts

@@ -68,12 +68,14 @@ export default defineConfig({
             return 'xterm'
           }
           if (id.includes('node_modules')) {
+            // Arco 必须排在 vue 之前：它的 scope 名是 @arco-design/web-vue，
+            // 含 "vue" 子串，放在后面会被 vue-vendor 先吃掉。
+            if (id.includes('@arco-design')) {
+              return 'ui-vendor'
+            }
             if (id.includes('vue') || id.includes('pinia') || id.includes('vue-router')) {
               return 'vue-vendor'
             }
-            if (id.includes('naive-ui')) {
-              return 'ui-vendor'
-            }
             return 'vendor'
           }
         },
@@ -92,7 +94,7 @@ export default defineConfig({
       'vue',
       'vue-router',
       'pinia',
-      'naive-ui',
+      '@arco-design/web-vue',
     ],
   },
   server: {