feat(F006-W3.6): 暗色 logo 亮版(dark 主题对比度)

- 新增 src/assets/logo-jubian-light.png:PIL 重映射所有非透明像素
  字色 #190564 → #F8FAFC (= dark 主题 --ink),透明底保留
- LoginView.vue + AppLayout.vue:logo 改 :src="logoSrc",computed 跟
  themeStore.current 切换;dark 主题下显示亮版,其他主题保持原深紫版
- 修 AGENTS.md §W5.x 一期已知风险("Dark 主题下 logo 字色 #190564
  可能对比度低 → 二期做亮版 logo")

src/components/AppLayout/AppLayout.vue

@@ -11,6 +11,9 @@ import { computed, onMounted, ref } from 'vue'
 import { useRouter, useRoute } from 'vue-router'
 import ThemePicker from '@/components/ThemePicker/ThemePicker.vue'
 import { useUserStore } from '@/stores/user'
+import { useThemeStore } from '@/stores/theme'
+import logoUrl from '@/assets/logo-jubian.png'
+import logoLightUrl from '@/assets/logo-jubian-light.png'
 import { useMenuStore, type MenuItem } from '@/stores/menu'
 import {
   Odometer, Box, Document, ChatLineSquare, ChatDotRound, OfficeBuilding,
@@ -24,6 +27,8 @@ import {
 const router = useRouter()
 const route = useRoute()
 const userStore = useUserStore()
+const themeStore = useThemeStore()
+const logoSrc = computed(() => themeStore.current === 'dark' ? logoLightUrl : logoUrl)
 const menuStore = useMenuStore()
 
 const collapsed = computed(() => menuStore.collapsed)
@@ -236,7 +241,7 @@ onMounted(loadBadges)
     <aside class="rr-sidebar">
       <!-- 品牌 + 搜索框(只在展开时显示) -->
       <div class="rr-sidebar-brand" v-if="!collapsed">
-        <img class="rr-sidebar-logo" src="@/assets/logo-jubian.png" alt="巨变" />
+        <img class="rr-sidebar-logo" :src="logoSrc" alt="巨变" />
         <span class="rr-sidebar-name">产业互联网平台运营后台</span>
       </div>
 

src/modules/auth/LoginView.vue

@@ -17,11 +17,15 @@ import qs from 'qs'
 import axios from 'axios'
 import { useUserStore } from '@/stores/user'
 import { useThemeStore } from '@/stores/theme'
+import { computed } from 'vue'
+import logoUrl from '@/assets/logo-jubian.png'
+import logoLightUrl from '@/assets/logo-jubian-light.png'
 
 const router = useRouter()
 const route = useRoute()
 const userStore = useUserStore()
 const themeStore = useThemeStore()
+const logoSrc = computed(() => themeStore.current === 'dark' ? logoLightUrl : logoUrl)
 
 const form = reactive({
   username: 'admin',
@@ -99,7 +103,7 @@ async function onLogin() {
       <!-- 左 65%: 品牌区 -->
       <div class="rr-login-left">
         <div class="rr-login-brand">
-          <img class="rr-login-logo" src="@/assets/logo-jubian.png" alt="巨变" />
+          <img class="rr-login-logo" :src="logoSrc" alt="巨变" />
           <div class="rr-login-product-name">产业互联网平台运营后台</div>
         </div>