v0.2.1

Added

• write_file tool — agents can now create new files (refuses to overwrite existing ones)
• Integration tests for edit_file with multi-byte (emoji) content

Changed

• Personality adjustments
• Better write_file output formatting

Fixed

• Fix path traversal vulnerability in validate_relative_path for non-existent paths
• Fix: guarantee all markers are removed after agent completes, not just context markers
• Make keyboard Space-bar polling Unix-only (termios unavailable on Windows); no-op on non-Unix platforms