feat: add transaction hash search to blockchain explorer and cleanup settlement storage

Blockchain Explorer:
- Add transaction hash search support (64-char hex pattern validation)
- Fetch and display transaction details in modal (hash, type, from/to, amount, fee, block)
- Fix regex escape sequence in block height validation
- Update search placeholder text to mention both search types
- Add blank lines between function definitions for PEP 8 compliance

Settlement Storage:
- Add timedelta import for future

docs/8_development/17_windsurf-testing.md

@@ -27,13 +27,21 @@ This guide explains how to use Windsurf's integrated testing features with the A
 ### 4. Pytest Configuration
 - ✅ `pyproject.toml` - Main configuration with markers
 - ✅ `pytest.ini` - Moved to project root with custom markers
-- ✅ `tests/conftest.py` - Fixtures with fallback mocks
+- ✅ `tests/conftest.py` - Fixtures with fallback mocks and test environment setup
 
 ### 5. Test Scripts (2026-01-29)
 - ✅ `scripts/testing/` - All test scripts moved here
 - ✅ `test_ollama_blockchain.py` - Complete GPU provider test
 - ✅ `test_block_import.py` - Blockchain block import testing
 
+### 6. Test Environment Improvements (2026-02-17)
+- ✅ **Confidential Transaction Service**: Created wrapper service for missing module
+- ✅ **Audit Logging**: Fixed permission issues using `/logs/audit/` directory
+- ✅ **Database Configuration**: Added test mode support and schema migration
+- ✅ **Integration Dependencies**: Comprehensive mocking for optional dependencies
+- ✅ **Import Path Resolution**: Fixed complex module structure problems
+- ✅ **Environment Variables**: Proper test environment configuration in conftest.py
+
 ## 🚀 How to Use
 
 ### Test Discovery