fix: resolve JSON parsing error and standardize HTTP client usage

- Fix JSON parsing error in getOrCreateGiteaOrg function (#19)
  - Add content-type validation before JSON parsing
  - Add response cloning for better error debugging
  - Enhance error messages with actual response content
  - Add comprehensive logging for troubleshooting

- Standardize HTTP client usage across codebase
  - Create new http-client.ts utility with consistent error handling
  - Replace all superagent calls with fetch-based functions
  - Replace all axios calls with fetch-based functions
  - Remove superagent, axios, and @types/superagent dependencies
  - Update tests to mock new HTTP client
  - Maintain backward compatibility

- Benefits:
  - Smaller bundle size (removed 3 HTTP client libraries)
  - Better performance (leveraging Bun's optimized fetch)
  - Consistent error handling across all HTTP operations
  - Improved debugging with detailed error messages
  - Easier maintenance with single HTTP client pattern

src/pages/api/health.ts

@@ -4,7 +4,7 @@ import { db } from "@/lib/db";
 import { ENV } from "@/lib/config";
 import { getRecoveryStatus, hasJobsNeedingRecovery } from "@/lib/recovery";
 import os from "os";
-import axios from "axios";
+import { httpGet } from "@/lib/http-client";
 
 // Track when the server started
 const serverStartTime = new Date();
@@ -197,9 +197,9 @@ async function checkLatestVersion(): Promise<string> {
 
   try {
     // Fetch the latest release from GitHub
-    const response = await axios.get(
+    const response = await httpGet(
       'https://api.github.com/repos/arunavo4/gitea-mirror/releases/latest',
-      { headers: { 'Accept': 'application/vnd.github.v3+json' } }
+      { 'Accept': 'application/vnd.github.v3+json' }
     );
 
     // Extract version from tag_name (remove 'v' prefix if present)