feat: 站点媒体库与移动端底部导航，服务测试补强

- 新增媒体库：media_library/media_thumbs 服务（WebP 缩略图）、管理端 media 页面
- 移动端底部导航 MobileTabBar 替换 MobilePostBar
- 旧数据导入增强与测试、路由与登录会话/板块侧边栏测试补强
- site-doc 组件精简（移除 Breadcrumb），文档新增迁移公告说明

backend/service/ad.go

@@ -38,11 +38,12 @@ var (
 	adImageUploadRe    = regexp.MustCompile(`(?i)^/uploads/(ads|images|brand)/[0-9a-f]{32}\.(png|jpe?g|gif|webp)$`)
 )
 
-// AdDurationOption 可购时长档位
+// AdDurationOption 可购时长档位（图片 / 文字广告分别计价）
 type AdDurationOption struct {
-	Days      int    `json:"days"`
-	Label     string `json:"label"`
-	PriceHint string `json:"price_hint"`
+	Days          int    `json:"days"`
+	Label         string `json:"label"`
+	PriceHint     string `json:"price_hint"`      // 图片广告价格
+	PriceHintText string `json:"price_hint_text"` // 文字广告价格
 }
 
 // AdPaymentOption 收款方式（展示二维码，人工确认）
@@ -68,11 +69,11 @@ func DefaultAdConfig() AdConfig {
 		Enabled:    true,
 		PanelTitle: AdDefaultTitle,
 		Durations: []AdDurationOption{
-			{Days: 30, Label: "1 个月", PriceHint: ""},
-			{Days: 60, Label: "2 个月", PriceHint: ""},
-			{Days: 90, Label: "3 个月", PriceHint: ""},
-			{Days: 180, Label: "6 个月", PriceHint: ""},
-			{Days: 365, Label: "12 个月", PriceHint: ""},
+			{Days: 30, Label: "1 个月", PriceHint: "", PriceHintText: ""},
+			{Days: 60, Label: "2 个月", PriceHint: "", PriceHintText: ""},
+			{Days: 90, Label: "3 个月", PriceHint: "", PriceHintText: ""},
+			{Days: 180, Label: "6 个月", PriceHint: "", PriceHintText: ""},
+			{Days: 365, Label: "12 个月", PriceHint: "", PriceHintText: ""},
 		},
 		Payments: []AdPaymentOption{},
 	}
@@ -116,6 +117,9 @@ func (s *AdService) loadConfig() (AdConfig, error) {
 		if strings.TrimSpace(cfg.Durations[i].PriceHint) == "面议" {
 			cfg.Durations[i].PriceHint = ""
 		}
+		if strings.TrimSpace(cfg.Durations[i].PriceHintText) == "面议" {
+			cfg.Durations[i].PriceHintText = ""
+		}
 	}
 	return cfg, nil
 }
@@ -195,7 +199,14 @@ func normalizeAdConfig(in AdConfig) (AdConfig, error) {
 		if utf8.RuneCountInString(price) > 32 {
 			return AdConfig{}, ErrAdInvalid
 		}
-		durs = append(durs, AdDurationOption{Days: d.Days, Label: label, PriceHint: price})
+		priceText := strings.TrimSpace(d.PriceHintText)
+		if priceText == "面议" {
+			priceText = ""
+		}
+		if utf8.RuneCountInString(priceText) > 32 {
+			return AdConfig{}, ErrAdInvalid
+		}
+		durs = append(durs, AdDurationOption{Days: d.Days, Label: label, PriceHint: price, PriceHintText: priceText})
 	}
 	out.Durations = durs