增加即梦的生图和生视频功能

backend/internal/application/runtime_test.go

@@ -273,6 +273,21 @@ func TestProviderTargetsNeverSelectRemovedProvider(t *testing.T) {
 	}
 }
 
+func TestProviderVideoTargetsUseDocumentedSeedanceDefaults(t *testing.T) {
+	values := map[string]string{
+		"SEEDANCE_RATIO":      "16:9",
+		"SEEDANCE_DURATION":   "12",
+		"SEEDANCE_RESOLUTION": "1080p",
+	}
+	target := providerVideoTargets(func(name string) string { return values[name] })["seedance"]
+	if target.Model != "doubao-seedance-2-0-260128" {
+		t.Fatalf("model=%q", target.Model)
+	}
+	if target.Settings["ratio"] != "16:9" || target.Settings["duration"] != float64(12) || target.Settings["resolution"] != "1080p" {
+		t.Fatalf("settings=%#v", target.Settings)
+	}
+}
+
 func TestCapabilitySummaryMatchesConfiguredDefaultVideoEngine(t *testing.T) {
 	for _, test := range []struct {
 		name, engine, wantEngine, wantProvider, wantModel string