Add GitHub URLs and improve mock data for SWE-bench

- Generate 300 mock tasks with better difficulty distribution
- Include GitHub issue/PR URLs in task data
- Mark mock data with _is_mock flag for validation
- Improve error messages and logging

🤖 Generated with Claude Code

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

backend/swe_bench_service.py

@@ -142,10 +142,13 @@ ValueError: invalid literal for int() with base 10: '[]'
 Expected behavior: Should return an empty list []"""
         ]
 
-        for i in range(100):  # Create 100 mock tasks
+        for i in range(300):  # Create 300 mock tasks for better testing
             repo = repos[i % len(repos)]
+            repo_name = repo.split('/')[1]
+            issue_number = 11000 + i
+
             task = SWEBenchTask(
-                instance_id=f"{repo.split('/')[1]}__{i+11000}",
+                instance_id=f"{repo_name}__{repo_name}-{issue_number}",
                 repo=repo,
                 problem_statement=statements[i % len(statements)],
                 base_commit=f"commit_{i:04d}",
@@ -237,7 +240,14 @@ Expected behavior: Should return an empty list []"""
                 'created_at': t.created_at,
                 'has_patch': t.patch is not None,
                 'has_tests': t.test_patch is not None,
-                'test_count': len(t.FAIL_TO_PASS) if t.FAIL_TO_PASS else 0
+                'test_count': len(t.FAIL_TO_PASS) if t.FAIL_TO_PASS else 0,
+                # Add GitHub URLs if this looks like a real GitHub repo
+                'issue_url': f"https://github.com/{t.repo}/issues/{t.instance_id.split('-')[-1]}"
+                    if '/' in t.repo and t.instance_id else None,
+                'pr_url': f"https://github.com/{t.repo}/pull/{t.instance_id.split('-')[-1]}"
+                    if '/' in t.repo and t.instance_id else None,
+                # Mark mock data
+                '_is_mock': not hasattr(t, 'issue_url')  # Real tasks would have issue_url attribute
             }
             for t in tasks
         ]