fix: enhance priority handling in sort-config and JiraService

- Added a fallback mechanism in getPriorityValue to default to 'medium' when an unknown priority is encountered, improving robustness.
- Updated priority mapping in JiraService to change 'Highest' to 'urgent', aligning with new priority definitions.

services/jira.ts

@@ -607,7 +607,7 @@ export class JiraService {
     if (!jiraPriority) return 'medium';
 
     const priorityMapping: Record<string, string> = {
-      'Highest': 'critical',
+      'Highest': 'urgent',
       'High': 'high', 
       'Medium': 'medium',
       'Low': 'low',