完善生图5.0的功能

backend/internal/httpapi/jobs.go

@@ -458,10 +458,22 @@ func writeJobError(w http.ResponseWriter, err error, public bool) {
 		message := "生成任务计费失败。"
 		if public {
 			message = "Generation job billing failed."
+		} else if errors.Is(err, billing.ErrInsufficientBalance) {
+			message = "余额不足，请先充值。"
+		} else if errors.Is(err, billing.ErrOrganizationUnavailable) {
+			message = "账号未绑定有效组织，请联系管理员。"
 		}
 		writeJSON(w, billingStatus.Status, map[string]string{"error": message})
 		return
 	}
+	if errors.Is(err, billing.ErrProviderUnavailable) {
+		message := "计费服务暂不可用，请稍后重试。"
+		if public {
+			message = "Generation billing is temporarily unavailable."
+		}
+		writeJSON(w, http.StatusServiceUnavailable, map[string]string{"error": message})
+		return
+	}
 	writeJSON(w, 500, map[string]string{"error": "Internal server error."})
 }
 func randomJobID() string {

backend/internal/httpapi/jobs_test.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"strings"
@@ -231,7 +232,7 @@ func TestJobsHTTPMapsBillingChargeErrorsAndPublicUsesPublicCreation(t *testing.T
 	h, _ := NewJobsHandler(JobsDependencies{Service: jobs.NewService(store, time.Now), Platform: platform, Public: publicapi.NewAuthenticator(publicapi.Config{APIKeys: "agent-a:secret"}), Builder: &jobBuilderStub{}, Creation: creation}, JobsConfig{})
 	w := httptest.NewRecorder()
 	h.ServeHTTP(w, httptest.NewRequest(http.MethodPost, "/api/generations/image", bytes.NewBufferString(`{"prompt":"hello"}`)))
-	if w.Code != 402 || w.Body.String() != "{\"error\":\"生成任务计费失败。\"}\n" {
+	if w.Code != 402 || w.Body.String() != "{\"error\":\"余额不足，请先充值。\"}\n" {
 		t.Fatalf("platform=%d %s", w.Code, w.Body.String())
 	}
 	creation.err = nil
@@ -246,13 +247,16 @@ func TestJobsHTTPMapsBillingChargeErrorsAndPublicUsesPublicCreation(t *testing.T
 
 func TestJobsHTTPMapsAllCreationBillingOutcomesWithoutLeakingErrors(t *testing.T) {
 	tests := []struct {
-		name string
-		err  error
-		want int
+		name    string
+		err     error
+		want    int
+		message string
 	}{
-		{name: "insufficient", err: &billing.StatusError{Status: 402, Err: billing.ErrInsufficientBalance}, want: 402},
-		{name: "idempotency", err: &billing.StatusError{Status: 409, Err: billing.ErrIdempotencyConflict}, want: 409},
-		{name: "unknown", err: errors.New("postgres password leaked"), want: 500},
+		{name: "insufficient", err: &billing.StatusError{Status: 402, Err: billing.ErrInsufficientBalance}, want: 402, message: "余额不足，请先充值。"},
+		{name: "organization", err: &billing.StatusError{Status: 409, Err: billing.ErrOrganizationUnavailable}, want: 409, message: "账号未绑定有效组织，请联系管理员。"},
+		{name: "idempotency", err: &billing.StatusError{Status: 409, Err: billing.ErrIdempotencyConflict}, want: 409, message: "生成任务计费失败。"},
+		{name: "unavailable", err: billing.ErrProviderUnavailable, want: 503, message: "计费服务暂不可用，请稍后重试。"},
+		{name: "unknown", err: errors.New("postgres password leaked"), want: 500, message: "Internal server error."},
 	}
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
@@ -262,7 +266,7 @@ func TestJobsHTTPMapsAllCreationBillingOutcomesWithoutLeakingErrors(t *testing.T
 			h, _ := NewJobsHandler(JobsDependencies{Service: jobs.NewService(store, time.Now), Platform: platform, Public: publicapi.NewAuthenticator(publicapi.Config{APIKeys: "agent-a:secret"}), Builder: &jobBuilderStub{}, Creation: creation}, JobsConfig{})
 			w := httptest.NewRecorder()
 			h.ServeHTTP(w, httptest.NewRequest(http.MethodPost, "/api/generations/image", bytes.NewBufferString(`{"prompt":"hello"}`)))
-			if w.Code != test.want || strings.Contains(w.Body.String(), "postgres") {
+			if w.Code != test.want || w.Body.String() != fmt.Sprintf("{\"error\":%q}\n", test.message) || strings.Contains(w.Body.String(), "postgres") {
 				t.Fatalf("status=%d body=%s", w.Code, w.Body.String())
 			}
 		})

backend/internal/httpapi/openapi.go

@@ -96,7 +96,7 @@ func openAPISchemas() map[string]any {
 				"capability":    openAPIRef("GenerationCapability"),
 				"engine":        map[string]any{"type": "string", "enum": []string{"jimeng", "seedream", "evolink", "bailian", "seedance"}},
 				"model":         map[string]any{"type": "string", "enum": []string{"doubao-seedance-2-0-260128", "doubao-seedance-2-5-260628"}, "description": "Optional allow-listed Seedance model for video.generate."},
-				"prompt":        map[string]any{"type": "string", "description": "Prompt text. Required for image.generate unless promptAssembly is supplied."},
+				"prompt":        map[string]any{"type": "string", "description": "Prompt text. Required for generation except Seedream layer decomposition, where an empty prompt triggers automatic decomposition."},
 				"inputUrls":     map[string]any{"type": "array", "items": map[string]any{"type": "string", "format": "uri"}, "description": "Reference image URLs for image capabilities."},
 				"imageUrls":     map[string]any{"type": "array", "items": map[string]any{"type": "string", "format": "uri"}, "description": "Alias for image input URLs."},
 				"inputAssetIds": openAPIStringArray(),
@@ -104,12 +104,14 @@ func openAPISchemas() map[string]any {
 				"settings": map[string]any{
 					"type": "object", "description": "Provider-specific image or video settings.",
 					"properties": map[string]any{
-						"ratio":        map[string]any{"type": "string", "enum": []string{"16:9", "4:3", "1:1", "3:4", "9:16", "21:9", "adaptive"}},
-						"duration":     map[string]any{"type": "integer", "minimum": 4, "maximum": 30, "description": "Seedance 2.0 supports up to 15 seconds; Seedance 2.5 supports up to 30 seconds."},
-						"resolution":   map[string]any{"type": "string", "enum": []string{"480p", "720p", "1080p"}},
-						"size":         map[string]any{"type": "string", "enum": []string{"1K", "1.5K", "2K"}, "description": "Seedream 5.0 Pro output size."},
-						"outputFormat": map[string]any{"type": "string", "enum": []string{"png", "jpeg"}},
-						"optimizeMode": map[string]any{"type": "string", "enum": []string{"standard", "fast"}},
+						"ratio":              map[string]any{"type": "string", "enum": []string{"16:9", "4:3", "1:1", "3:4", "9:16", "21:9", "adaptive"}},
+						"duration":           map[string]any{"type": "integer", "minimum": 4, "maximum": 30, "description": "Seedance 2.0 supports up to 15 seconds; Seedance 2.5 supports up to 30 seconds."},
+						"resolution":         map[string]any{"type": "string", "enum": []string{"480p", "720p", "1080p"}},
+						"size":               map[string]any{"type": "string", "enum": []string{"auto", "1K", "1.5K", "2K"}, "description": "Seedream 5.0 Pro output size. auto is available for layer decomposition only."},
+						"outputFormat":       map[string]any{"type": "string", "enum": []string{"png", "jpeg"}},
+						"optimizeMode":       map[string]any{"type": "string", "enum": []string{"standard", "fast"}},
+						"creationMode":       map[string]any{"type": "string", "enum": []string{"basic", "interactive", "layers"}, "description": "Seedream 5.0 Pro image workflow."},
+						"layerDecomposition": map[string]any{"type": "boolean", "description": "Enables Seedream 5.0 Pro layer decomposition; exactly one image is required."},
 					},
 				},
 				"width":          map[string]any{"type": "integer", "example": 1440},