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/service_policy_helpers.go

@@ -0,0 +1,52 @@
+package service
+
+import (
+	"strings"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+	"stream.api/internal/database/model"
+)
+
+func ensurePaidPlan(user *model.User) error {
+	if user == nil {
+		return status.Error(codes.Unauthenticated, "Unauthorized")
+	}
+	if user.PlanID == nil || strings.TrimSpace(*user.PlanID) == "" {
+		return status.Error(codes.PermissionDenied, adTemplateUpgradeRequiredMessage)
+	}
+	return nil
+}
+
+func playerConfigActionAllowed(user *model.User, configCount int64, action string) error {
+	if user == nil {
+		return status.Error(codes.Unauthenticated, "Unauthorized")
+	}
+	if user.PlanID != nil && strings.TrimSpace(*user.PlanID) != "" {
+		return nil
+	}
+
+	switch action {
+	case "create":
+		if configCount > 0 {
+			return status.Error(codes.FailedPrecondition, playerConfigFreePlanLimitMessage)
+		}
+		return nil
+	case "delete":
+		return nil
+	case "update", "set-default", "toggle-active":
+		if configCount > 1 {
+			return status.Error(codes.FailedPrecondition, playerConfigFreePlanReconciliationMessage)
+		}
+		return nil
+	default:
+		return nil
+	}
+}
+
+func safeRole(role *string) string {
+	if role == nil || strings.TrimSpace(*role) == "" {
+		return "USER"
+	}
+	return *role
+}