feat(import): refine official release metadata backfill

scripts/import_phase2_data_test.go

@@ -10,6 +10,16 @@ func TestEnrichBaiduModelMetadataUsesSpecificFamilyRules(t *testing.T) {
 		wantReleaseDate string
 		wantSourceURL   string
 	}{
+		{
+			modelID:         "baidu-ernie-5.0",
+			wantReleaseDate: "2026-01-22",
+			wantSourceURL:   "https://cloud.baidu.com/news/news_eacd0f0b-0ca3-4963-aec8-5e6b9ebef9ba",
+		},
+		{
+			modelID:         "baidu-ernie-x1.1",
+			wantReleaseDate: "2025-09-09",
+			wantSourceURL:   "https://cloud.baidu.com/news/news_be713ff4-8477-4852-88f1-9cc56c406d6a",
+		},
 		{
 			modelID:         "baidu-ernie-4.5-turbo-128k",
 			wantReleaseDate: "2025-04-25",
@@ -30,6 +40,11 @@ func TestEnrichBaiduModelMetadataUsesSpecificFamilyRules(t *testing.T) {
 			wantReleaseDate: "2025-03-16",
 			wantSourceURL:   "https://cloud.baidu.com/article/3835921",
 		},
+		{
+			modelID:         "baidu-ernie-character",
+			wantReleaseDate: "2024-03-22",
+			wantSourceURL:   "https://cloud.baidu.com/news/news_667c065f-0bd7-475d-98c2-901763d0ee77",
+		},
 	}
 
 	for _, tc := range cases {
@@ -61,6 +76,20 @@ func TestEnrichBaiduModelMetadataFallsBackToPricingSource(t *testing.T) {
 	}
 }
 
+func TestEnrichBaiduModelMetadataSupportsSourceOnlyRules(t *testing.T) {
+	enriched := enrichBaiduModelMetadata(ModelPricing{
+		ModelID:   "baidu-ernie-5.1",
+		SourceURL: "https://cloud.baidu.com/doc/qianfan/s/wmh4sv6ya",
+	})
+
+	if enriched.ReleaseDate != "" {
+		t.Fatalf("unexpected release date: %q", enriched.ReleaseDate)
+	}
+	if enriched.ModelSourceURL != "https://cloud.baidu.com/product/wenxinworkshop.html" {
+		t.Fatalf("model source url = %q, want product source", enriched.ModelSourceURL)
+	}
+}
+
 func TestBaiduReleaseDateValueReturnsNilForUnknownDate(t *testing.T) {
 	if value := releaseDateValue(""); value != nil {
 		t.Fatalf("blank release date should stay nil, got %v", value)