feat: Implement video workflow repository and related services

- Added videoWorkflowRepository with methods to manage video and user interactions.
- Introduced catalog_mapper for converting database models to protobuf representations.
- Created domain_helpers for normalizing domain and ad format values.
- Defined service interfaces for payment, account, notification, domain, ad template, player config, video, and user management.
- Implemented OAuth helpers for generating state and caching keys.
- Developed payment_proto_helpers for mapping payment-related models to protobuf.
- Added service policy helpers to enforce plan requirements and user permissions.
- Created user_mapper for converting user payloads to protobuf format.
- Implemented value_helpers for handling various value conversions and nil checks.
- Developed video_helpers for normalizing video statuses and managing storage types.
- Created video_mapper for mapping video models to protobuf format.
- Implemented render workflow for managing video creation and job processing.

internal/service/video_mapper.go

@@ -0,0 +1,55 @@
+package service
+
+import (
+	"context"
+	"strings"
+
+	"google.golang.org/protobuf/types/known/timestamppb"
+	appv1 "stream.api/internal/api/proto/app/v1"
+	"stream.api/internal/database/model"
+)
+
+func toProtoVideo(item *model.Video, jobID ...string) *appv1.Video {
+	if item == nil {
+		return nil
+	}
+	statusValue := stringValue(item.Status)
+	if statusValue == "" {
+		statusValue = "ready"
+	}
+	var linkedJobID *string
+	if len(jobID) > 0 {
+		linkedJobID = stringPointerOrNil(jobID[0])
+	}
+	return &appv1.Video{
+		Id:               item.ID,
+		UserId:           item.UserID,
+		Title:            item.Title,
+		Description:      item.Description,
+		Url:              item.URL,
+		Status:           strings.ToLower(statusValue),
+		Size:             item.Size,
+		Duration:         item.Duration,
+		Format:           item.Format,
+		Thumbnail:        item.Thumbnail,
+		ProcessingStatus: item.ProcessingStatus,
+		StorageType:      item.StorageType,
+		CreatedAt:        timeToProto(item.CreatedAt),
+		UpdatedAt:        timestamppb.New(item.UpdatedAt.UTC()),
+		JobId:            linkedJobID,
+	}
+}
+
+func (s *videosAppService) buildVideo(ctx context.Context, video *model.Video) (*appv1.Video, error) {
+	if video == nil {
+		return nil, nil
+	}
+	jobID, err := s.loadLatestVideoJobID(ctx, video.ID)
+	if err != nil {
+		return nil, err
+	}
+	if jobID != nil {
+		return toProtoVideo(video, *jobID), nil
+	}
+	return toProtoVideo(video), nil
+}