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

tests/client/default-credential-prompt.test.ts

@@ -1,7 +1,8 @@
 // @vitest-environment jsdom
 import { beforeEach, describe, expect, it, vi } from 'vitest'
-import { nextTick } from 'vue'
+import { defineComponent, nextTick } from 'vue'
 import { flushPromises, mount } from '@vue/test-utils'
+import ArcoVue from '@arco-design/web-vue'
 
 const mockPush = vi.hoisted(() => vi.fn())
 const mockFetchCurrentUser = vi.hoisted(() => vi.fn())
@@ -27,30 +28,23 @@ vi.mock('@/api/client', () => ({
   getApiKey: mockGetApiKey,
 }))
 
-vi.mock('naive-ui', async () => {
-  const { defineComponent, h } = await import('vue')
-  return {
-    NModal: defineComponent({
-      props: { show: Boolean, title: String },
-      setup(props, { slots }) {
-        return () => props.show
-          ? h('div', { class: 'modal' }, [
-            h('h2', props.title),
-            slots.default?.(),
-            h('div', { class: 'modal-actions' }, slots.action?.()),
-          ])
-          : null
-      },
-    }),
-    NButton: defineComponent({
-      emits: ['click'],
-      setup(_props, { emit, slots }) {
-        return () => h('button', { onClick: () => emit('click') }, slots.default?.())
-      },
-    }),
-  }
+// a-modal teleports to body in jsdom, so render it inline through a stub keyed
+// by Arco's internal component name.
+const AModalStub = defineComponent({
+  name: 'Modal',
+  props: { visible: Boolean, title: String },
+  emits: ['update:visible'],
+  template: '<div v-if="visible" class="arco-modal-stub"><h2>{{ title }}</h2><slot /><div class="modal-actions"><slot name="footer" /></div></div>',
 })
 
+const arcoGlobal = { plugins: [ArcoVue], stubs: { Modal: AModalStub } }
+
+function buttonByText(wrapper: any, text: string) {
+  const button = wrapper.findAll('button').find((node: any) => node.text().trim() === text)
+  if (!button) throw new Error(`no button labelled "${text}"`)
+  return button
+}
+
 import DefaultCredentialPrompt from '@/components/auth/DefaultCredentialPrompt.vue'
 
 describe('DefaultCredentialPrompt', () => {
@@ -74,13 +68,14 @@ describe('DefaultCredentialPrompt', () => {
       requiresCredentialChange: true,
     })
 
-    const wrapper = mount(DefaultCredentialPrompt)
+    const wrapper = mount(DefaultCredentialPrompt, { global: arcoGlobal })
     await flushPromises()
     await nextTick()
 
     expect(mockFetchCurrentUser).toHaveBeenCalledOnce()
     expect(wrapper.text()).toContain('login.defaultCredentialMessage')
-    await wrapper.findAll('button')[1].trigger('click')
+
+    await buttonByText(wrapper, 'login.defaultCredentialAction').trigger('click')
     expect(mockPush).toHaveBeenCalledWith({ name: 'hermes.settings', query: { tab: 'account' } })
   })
 
@@ -88,7 +83,7 @@ describe('DefaultCredentialPrompt', () => {
     routeState.fullPath = '/'
     routeState.name = 'login'
 
-    mount(DefaultCredentialPrompt)
+    mount(DefaultCredentialPrompt, { global: arcoGlobal })
     await Promise.resolve()
 
     expect(mockFetchCurrentUser).not.toHaveBeenCalled()