Fix SWE-bench service to return full problem statements

- Return complete problem_statement instead of truncating at 500 chars
- Enables frontend to display full multi-line issue descriptions
- Fixes issue where problems were showing as one-liners

🤖 Generated with [Claude Code](https://claude.ai/code)

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

backend/swe_bench_service.py

@@ -163,7 +163,7 @@ class SWEBenchService:
                 'repo': t.repo,
                 'category': t.category,
                 'difficulty': t.difficulty,
-                'problem_statement': t.problem_statement[:500] + '...' if len(t.problem_statement) > 500 else t.problem_statement,
+                'problem_statement': t.problem_statement,  # Return full problem statement
                 'created_at': t.created_at,
                 'has_patch': t.patch is not None,
                 'has_tests': t.test_patch is not None,
@@ -190,6 +190,7 @@ class SWEBenchService:
             'version': task.version,
             'patch_preview': task.patch[:1000] if task.patch else None,
             'test_preview': task.test_patch[:1000] if task.test_patch else None,
+            'gold_patch': task.patch,  # Include full gold patch
             'fail_to_pass': task.FAIL_TO_PASS,
             'pass_to_pass': task.PASS_TO_PASS,
             'patch_size': len(task.patch.split('\n')) if task.patch else 0,