chore(gitignore): add development tests exclusion patterns

- Add dev/tests/__pycache__/ Python cache directory
- Add dev/tests/*.pyc compiled Python files
- Add dev/tests/test_results/ test output directory
- Add dev/tests/simple_test_results.json test results file
- Add dev/tests/data/ test data directory
- Add dev/tests/*.db test database files

dev/tests/README.md

@@ -0,0 +1,26 @@
+# Development Tests
+
+This directory contains ad-hoc development tests and experimental scripts.
+
+## Purpose
+
+- Quick validation during development
+- Multi-chain testing scenarios
+- API submission experiments
+- Cross-site testing
+- Performance validation scripts
+
+## Usage
+
+These tests are meant for development use only and may not be suitable for CI/CD pipelines.
+
+## Structure
+
+- `test_multi_chain*.py` - Multi-chain blockchain testing
+- `test_api_submit*.py` - API submission testing
+- `test_*.sh` - Shell script test scenarios
+- `simple_test_results.json` - Test results storage
+
+## Note
+
+For production-ready tests, see the main `/tests/` directory.