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/pages/api/job/mirror-repo.ts

@@ -73,9 +73,10 @@ export const POST: APIRoute = async ({ request }) => {
         throw new Error("GitHub token is missing.");
       }
 
-      // Create a single Octokit instance to be reused
+      // Create a single Octokit instance to be reused with rate limit tracking
       const decryptedToken = getDecryptedGitHubToken(config);
-      const octokit = createGitHubClient(decryptedToken);
+      const githubUsername = config.githubConfig?.owner || undefined;
+      const octokit = createGitHubClient(decryptedToken, userId, githubUsername);
 
       // Define the concurrency limit - adjust based on API rate limits
       const CONCURRENCY_LIMIT = 3;