Added Github API rate limiting

- Implemented comprehensive GitHub API rate limit handling:
    - Integrated @octokit/plugin-throttling for automatic retry with exponential backoff
    - Added RateLimitManager service to track and enforce rate limits
    - Store rate limit status in database for persistence across restarts
    - Automatic pause and resume when limits are exceeded
    - Proper user identification for 5000 req/hr authenticated limit (vs 60 unauthenticated)

  - Improved rate limit UI/UX:
    - Removed intrusive rate limit card from dashboard
    - Toast notifications only at critical thresholds (80% and 100% usage)
    - All rate limit events logged for debugging

  - Optimized for GitHub's API constraints:
    - Reduced default batch size from 10 to 5 repositories
    - Added documentation about GitHub's 100 concurrent request limit
    - Better handling of repositories with many issues/PRs

src/lib/repository-cleanup-service.ts

@@ -23,9 +23,10 @@ async function identifyOrphanedRepositories(config: any): Promise<any[]> {
   const userId = config.userId;
   
   try {
-    // Get current GitHub repositories
+    // Get current GitHub repositories with rate limit tracking
     const decryptedToken = getDecryptedGitHubToken(config);
-    const octokit = createGitHubClient(decryptedToken);
+    const githubUsername = config.githubConfig?.owner || undefined;
+    const octokit = createGitHubClient(decryptedToken, userId, githubUsername);
     
     let allGithubRepos = [];
     let githubApiAccessible = true;