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/value_helpers.go

@@ -0,0 +1,83 @@
+package service
+
+import (
+	"strings"
+	"time"
+
+	"google.golang.org/protobuf/types/known/timestamppb"
+)
+
+func stringPointerOrNil(value string) *string {
+	trimmed := strings.TrimSpace(value)
+	if trimmed == "" {
+		return nil
+	}
+	return &trimmed
+}
+
+func timeToProto(value *time.Time) *timestamppb.Timestamp {
+	if value == nil {
+		return nil
+	}
+	return timestamppb.New(value.UTC())
+}
+
+func boolValue(value *bool) bool {
+	return value != nil && *value
+}
+
+func stringValue(value *string) string {
+	if value == nil {
+		return ""
+	}
+	return *value
+}
+
+func int32PtrToInt64Ptr(value *int32) *int64 {
+	if value == nil {
+		return nil
+	}
+	converted := int64(*value)
+	return &converted
+}
+
+func int64PtrToInt32Ptr(value *int64) *int32 {
+	if value == nil {
+		return nil
+	}
+	converted := int32(*value)
+	return &converted
+}
+
+func int32Ptr(value int32) *int32 {
+	return &value
+}
+
+func protoStringValue(value *string) string {
+	if value == nil {
+		return ""
+	}
+	return strings.TrimSpace(*value)
+}
+
+func nullableTrimmedStringPtr(value *string) *string {
+	if value == nil {
+		return nil
+	}
+	trimmed := strings.TrimSpace(*value)
+	if trimmed == "" {
+		return nil
+	}
+	return &trimmed
+}
+
+func nullableTrimmedString(value *string) *string {
+	if value == nil {
+		return nil
+	}
+	trimmed := strings.TrimSpace(*value)
+	if trimmed == "" {
+		return nil
+	}
+	return &trimmed
+}