v8.4.0

What's Changed

Bug Fixes

• Windows unittest database locking (#291): Fixed SQLite file locking issues on Windows by force-closing StaticPool DBAPI connections and properly releasing file locks before database deletion
• Unicode encoding: Fixed UnicodeEncodeError in validate_backtest_checkpoints on Windows (cp1252 → utf-8)
• Test isolation: Added teardown_sqlalchemy() to all test teardowns to prevent stale database state between tests

New Features

• Record function (#455): Added ability to record custom variables during strategy execution and backtesting

CI/CD

• Added Windows to CI test matrix (ubuntu, macos, windows × Python 3.10, 3.11)
• Per-OS test status badges in README (Linux, macOS, Windows for main and dev)
• Increased CI timeout to 40 minutes for Windows coverage runs

Chores

• Removed scripts/ directory
• Renamed test data files with Windows-incompatible characters (colons → dashes)