feat(tests): implement high volume stress testing framework

Add comprehensive stress testing solution for SDK using arun_many and dispatcher system:
- Create test_stress_sdk.py for running high volume crawl tests
- Add run_benchmark.py for orchestrating tests with predefined configs
- Implement benchmark_report.py for generating performance reports
- Add memory tracking and local test site generation
- Support both streaming and batch processing modes
- Add detailed documentation in README.md

The framework enables testing SDK performance, concurrency handling,
and memory behavior under high-volume scenarios.

.gitignore

@@ -257,4 +257,8 @@ continue_config.json
 .private/
 
 CLAUDE_MONITOR.md
-CLAUDE.md
+CLAUDE.md
+
+tests/**/test_site
+tests/**/reports
+tests/**/benchmark_reports