feat(listings): PC与移动端首页新增比例排序

- 前端选项：在 PC 首页（HomeView）与移动端首页（MobileHomeView）的排序项中，在「综合推荐」后新增「比例排序」（ratioDesc）
- 后端排序：在 sortPublicListings 中实现 ratioDesc/ratio，按折算比例从高到低排序，同比例按哈夫币数量降序次级平局决胜
- 自动化验证：新增 TestSortPublicListingsByRatio 单元测试，全量运行 ./scripts/check.sh 门禁（Go测试、MySQL测试、前端lint/typecheck/build）全部通过

backend/internal/modules/listing/public_filter.go

@@ -103,6 +103,20 @@ func sortPublicListings(items []ListingDTO, sortKey string) {
 			return a.PriceCent > b.PriceCent
 		case "coinDesc":
 			return a.HafCoinAmount > b.HafCoinAmount
+		case "ratioDesc", "ratio":
+			aRatio := ratioFromListing(a)
+			bRatio := ratioFromListing(b)
+			if aRatio != bRatio {
+				return aRatio > bRatio
+			}
+			return a.HafCoinAmount > b.HafCoinAmount
+		case "ratioAsc":
+			aRatio := ratioFromListing(a)
+			bRatio := ratioFromListing(b)
+			if aRatio != bRatio {
+				return aRatio < bRatio
+			}
+			return a.HafCoinAmount > b.HafCoinAmount
 		case "awmDesc":
 			aAmmo := resourceQuantity(a.AssetSummary, "awmAmmo")
 			bAmmo := resourceQuantity(b.AssetSummary, "awmAmmo")

backend/internal/modules/listing/public_filter_test.go

@@ -178,6 +178,45 @@ func TestSortPublicListingsDefaultUsesShuffleKey(t *testing.T) {
 	}
 }
 
+func TestSortPublicListingsByRatio(t *testing.T) {
+	items := []ListingDTO{
+		{
+			ID:            1,
+			HafCoinAmount: 50_000_000,
+			PriceCent:     5_000,
+			AssetSummary:  map[string]any{"publish_ratio": 20.0},
+		},
+		{
+			ID:            2,
+			HafCoinAmount: 50_000_000,
+			PriceCent:     2_500,
+			AssetSummary:  map[string]any{"publish_ratio": 45.0},
+		},
+		{
+			ID:            3,
+			HafCoinAmount: 80_000_000,
+			PriceCent:     3_000,
+			AssetSummary:  map[string]any{"publish_ratio": 35.0},
+		},
+		{
+			ID:            4,
+			HafCoinAmount: 100_000_000,
+			PriceCent:     4_000,
+			AssetSummary:  map[string]any{"publish_ratio": 35.0},
+		},
+	}
+
+	sortPublicListings(items, "ratioDesc")
+
+	// 预期顺序：ID=2 (45.0) > ID=4 (35.0, 100M 币更多) > ID=3 (35.0, 80M) > ID=1 (20.0)
+	expectedIDs := []uint64{2, 4, 3, 1}
+	for i, expected := range expectedIDs {
+		if items[i].ID != expected {
+			t.Fatalf("at index %d, expected listing %d, got %d (ratio=%.1f)", i, expected, items[i].ID, ratioFromListing(items[i]))
+		}
+	}
+}
+
 func TestIsNightAvailableSummaryUsesEarlyMorningResponse(t *testing.T) {
 	tests := []struct {
 		name     string

frontend/src/features/listings/views/HomeView.vue

@@ -72,6 +72,7 @@ const publishOptions = ref<ListingPublishOptions>(emptyListingPublishOptions)
 const sortBy = ref('recommended')
 const sortOptions = [
   { value: 'recommended', label: '综合推荐' },
+  { value: 'ratioDesc', label: '比例排序' },
   { value: 'coinDesc', label: '哈夫币' },
   { value: 'awmDesc', label: 'AWM数量' },
   { value: 'priceAsc', label: '价格最低' },

frontend/src/features/listings/views/MobileHomeView.vue

@@ -125,6 +125,7 @@ let searchDebounceTimer: ReturnType<typeof setTimeout> | null = null
 
 const sortOptions = [
   { key: 'recommended', label: '综合推荐' },
+  { key: 'ratioDesc', label: '比例排序' },
   { key: 'coinDesc', label: '哈夫币' },
   { key: 'awmDesc', label: 'AWM数量' },
   { key: 'priceAsc', label: '价格最低' },