feat: Implement stale validation cleanup and improve GitHub issue handling

- Added a scheduled task to clean up stale validation entries every hour, preventing memory leaks.
- Enhanced the `getAllValidations` function to read validation files in parallel for improved performance.
- Updated the `fetchLinkedPRs` function to use `spawn` for safer execution of GitHub CLI commands, mitigating shell injection risks.
- Modified event handling in the GitHub issues view to utilize the model for validation, ensuring consistency and reducing stale closure issues.
- Introduced a new property in the issue validation event to track the model used for validation.

apps/ui/src/components/views/github-issues-view.tsx

@@ -162,14 +162,14 @@ export function GitHubIssuesView() {
             return next;
           });
 
-          // Update cached validations (use event.issueTitle to avoid stale closure)
+          // Update cached validations (use event.model to avoid stale closure race condition)
           setCachedValidations((prev) => {
             const next = new Map(prev);
             next.set(event.issueNumber, {
               issueNumber: event.issueNumber,
               issueTitle: event.issueTitle,
               validatedAt: new Date().toISOString(),
-              model: validationModel,
+              model: event.model,
               result: event.result,
             });
             return next;

apps/ui/src/lib/electron.ts

@@ -2730,6 +2730,7 @@ function createMockGitHubAPI(): GitHubAPI {
             cb({
               type: 'issue_validation_complete',
               issueNumber: issue.issueNumber,
+              issueTitle: issue.issueTitle,
               result: {
                 verdict: 'valid' as const,
                 confidence: 'medium' as const,
@@ -2739,6 +2740,7 @@ function createMockGitHubAPI(): GitHubAPI {
                 estimatedComplexity: 'moderate' as const,
               },
               projectPath,
+              model: model || 'sonnet',
             })
           );
         }, 2000);
@@ -2772,6 +2774,12 @@ function createMockGitHubAPI(): GitHubAPI {
         validations: [],
       };
     },
+    markValidationViewed: async (projectPath: string, issueNumber: number) => {
+      console.log('[Mock] Marking validation as viewed:', { projectPath, issueNumber });
+      return {
+        success: true,
+      };
+    },
     onValidationEvent: (callback: (event: IssueValidationEvent) => void) => {
       mockValidationCallbacks.push(callback);
       return () => {