fix(worker): 将 Gemini 同步请求交由异步队列执行

将非流式 Gemini generateContent 改为 River Worker 执行，API 通过批量状态查询等待完成，避免高并发同步请求耗尽 API 数据库连接池。\n\n生成图片在持久化时保存带哈希的资产引用，响应恢复时下载并校验后重建 Base64，数据库不保存媒体原文。请求体物化增加前置内存门禁，并扩展双 API/Worker PostgreSQL 压力测试。\n\n验证：go test ./... -count=1；go vet ./...；pnpm openapi；迁移安全检查；64 与 256 请求双角色异步 Gemini 压力测试。

apps/api/internal/runner/binary_results.go

@@ -17,6 +17,7 @@ import (
 
 	"github.com/easyai/easyai-ai-gateway/apps/api/internal/clients"
 	"github.com/easyai/easyai-ai-gateway/apps/api/internal/config"
+	"github.com/easyai/easyai-ai-gateway/apps/api/internal/store"
 )
 
 const (
@@ -405,6 +406,17 @@ func (s *Service) hydrateLocalBinaryValue(ctx context.Context, taskID string, va
 	}
 	switch typed := value.(type) {
 	case map[string]any:
+		if ref, ok := generatedResultAssetReference(typed); ok {
+			payload, contentType, err := s.readGeneratedResultAsset(ctx, ref)
+			if err != nil {
+				return nil, false, err
+			}
+			encoded := base64.StdEncoding.EncodeToString(payload)
+			if generatedResultAssetUsesDataURI(typed) {
+				return "data:" + contentType + ";base64," + encoded, true, nil
+			}
+			return encoded, true, nil
+		}
 		next := make(map[string]any, len(typed))
 		changed := false
 		for key, childValue := range typed {
@@ -453,6 +465,62 @@ func (s *Service) hydrateLocalBinaryValue(ctx context.Context, taskID string, va
 	}
 }
 
+func generatedResultAssetReference(value map[string]any) (store.RequestAsset, bool) {
+	ref, ok := value["assetRef"].(map[string]any)
+	if !ok {
+		return store.RequestAsset{}, false
+	}
+	storage, _ := value["assetStorage"].(map[string]any)
+	if stringFromAny(storage["scene"]) != store.FileStorageSceneImageResult {
+		return store.RequestAsset{}, false
+	}
+	asset := store.RequestAsset{
+		SHA256:          strings.ToLower(strings.TrimSpace(stringFromAny(ref["sha256"]))),
+		ContentType:     firstNonEmptyString(stringFromAny(ref["contentType"]), stringFromAny(storage["contentType"])),
+		URL:             firstNonEmptyString(stringFromAny(ref["url"]), stringFromAny(value["url"])),
+		StorageProvider: stringFromAny(ref["storageProvider"]),
+	}
+	if size := floatFromAny(ref["size"]); size > 0 {
+		asset.ByteSize = int64(size)
+	}
+	if expiresAt := stringFromAny(ref["expiresAt"]); expiresAt != "" {
+		if parsed, err := time.Parse(time.RFC3339, expiresAt); err == nil {
+			asset.ExpiresAt = &parsed
+		}
+	}
+	if asset.URL == "" || asset.SHA256 == "" || asset.ByteSize <= 0 {
+		return store.RequestAsset{}, false
+	}
+	return asset, true
+}
+
+func generatedResultAssetUsesDataURI(value map[string]any) bool {
+	storage, _ := value["assetStorage"].(map[string]any)
+	source := normalizeLocalBinaryKey(stringFromAny(storage["source"]))
+	return source == "datauri"
+}
+
+func (s *Service) readGeneratedResultAsset(ctx context.Context, asset store.RequestAsset) ([]byte, string, error) {
+	payload, err := s.readRequestAssetBytes(ctx, asset)
+	if err != nil {
+		return nil, "", err
+	}
+	digest := sha256.Sum256(payload)
+	if int64(len(payload)) != asset.ByteSize || hex.EncodeToString(digest[:]) != asset.SHA256 {
+		return nil, "", &clients.ClientError{
+			Code:       "binary_result_corrupted",
+			Message:    "stored result asset failed size or hash verification",
+			StatusCode: 500,
+			Retryable:  false,
+		}
+	}
+	contentType := strings.TrimSpace(asset.ContentType)
+	if contentType == "" {
+		contentType = "application/octet-stream"
+	}
+	return payload, contentType, nil
+}
+
 func (s *Service) readLocalBinaryResult(taskID string, descriptor localBinaryDescriptor) ([]byte, error) {
 	path := filepath.Join(s.localBinaryResultRoot(), safeLocalBinaryTaskDir(taskID), descriptor.SHA256+".bin")
 	info, err := os.Stat(path)