feat(distribution): 分站首页改为联名标题并同步手机轮播

首页主标题显示为站名×大锤商行，手机端使用与电脑端相同的分站自定义海报。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/stores/distributionSite.ts

@@ -14,6 +14,50 @@ export interface DistributionBanner {
   title?: string
 }
 
+export interface DistributionHomeBanner {
+  eyebrow: string
+  title: string
+  badge: string
+  pill: string
+  tone: string
+  image_url?: string
+}
+
+/** 分站首页主标题：站名与主站联名。主站或站名已含主站名时保持原样。 */
+export function formatDistributionCoBrandName(siteName: string, isDistribution: boolean): string {
+  const name = siteName.trim()
+  if (!isDistribution) return name || '大锤商行'
+  if (!name || name.includes('大锤商行')) return name || '大锤商行'
+  return `${name}×大锤商行`
+}
+
+/** 分站首页轮播：有图时不再叠标题，避免整幅压暗。 */
+export function mapDistributionHomeBanners(
+  banners: DistributionBanner[],
+  siteName: string
+): DistributionHomeBanner[] {
+  return banners.map(banner => {
+    const imageUrl = banner.image_url?.trim() || ''
+    if (imageUrl) {
+      return {
+        eyebrow: '',
+        title: '',
+        badge: '本店精选',
+        pill: '',
+        tone: 'gold',
+        image_url: imageUrl,
+      }
+    }
+    return {
+      eyebrow: siteName,
+      title: banner.title?.trim() || '精选游戏账号 · 随租随玩',
+      badge: '本店精选',
+      pill: '官方保障',
+      tone: 'gold',
+    }
+  })
+}
+
 export interface DistributionFooterInfo {
   icp?: string
   copyright?: string
@@ -92,6 +136,10 @@ export const useDistributionSiteStore = defineStore('distributionSite', {
     brandMark(state): string {
       return state.isDistribution && state.siteName ? state.siteName.slice(0, 1) : '锤'
     },
+    /** 分站首页主标题：站名与主站联名。 */
+    coBrandName(state): string {
+      return formatDistributionCoBrandName(state.siteName, state.isDistribution)
+    },
   },
 
   actions: {