feat: Enable migration resume capability and add safety improvements

- Remove label filter in duplicate detection to enable migration resume
- Add null check for closed_at timestamp to prevent crashes
- Add commitMap field to Settings interface for commit reference mapping

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: adamwestland

src/githubHelper.ts

@@ -181,7 +181,8 @@ export class GithubHelper {
         owner: this.githubOwner,
         repo: this.githubRepo,
         state: 'all',
-        labels: 'gitlab merge request',
+        // Remove label filter to get ALL issues for proper duplicate detection
+        // labels: 'gitlab merge request',
         per_page: perPage,
         page: page,
       });
@@ -496,7 +497,7 @@ export class GithubHelper {
       closed: issue.state === 'closed',
     };
 
-    if (issue.state === 'closed') {
+    if (issue.state === 'closed' && issue.closed_at) {
       props.closed_at = issue.closed_at;
     }
 

src/settings.ts

@@ -34,6 +34,9 @@ export default interface Settings {
     logFile: string;
     log: boolean;
   };
+  commitMap?: {
+    [key: string]: string;
+  };
   s3?: S3Settings;
 }