fix: Windows compatibility

[xobosox]

• Change hook command from python3 to py -3 (Python Launcher for Windows)
• Add quotes around path for paths with spaces
• Add -u flag for unbuffered output
• Add timeout of 10 seconds
• Add Windows stdin UTF-8 encoding handling
• Add flush=True to output for proper buffering
• Update README with Windows requirements and instructions

Windows doesn't have python3 command - it uses 'python' or 'py -3' (Python Launcher). The App Execution Alias for 'python' redirects to Microsoft Store, so 'py -3' is the most reliable cross-platform approach for Windows.

[severity1]

Thanks for the Windows compatibility work! The Python script changes (UTF-8 stdin handling, flush=True, better error handling) are great and backwards-compatible.

However, the hooks/hooks.json change from python3 to py -3 will break the plugin for Linux/macOS users since py (Python Launcher) is Windows-only.

Suggested approach: bash wrapper script

Instead of changing the Python interpreter directly, consider adding a cross-platform bash wrapper:

1. Create scripts/run-hook.sh:

#!/bin/bash
# Cross-platform wrapper to invoke Python with the correct interpreter
# - Linux/macOS: uses python3
# - Windows (Git Bash/MSYS/Cygwin): uses py -3

SCRIPT_DIR="$(dirname "$0")"
HOOK_SCRIPT="$SCRIPT_DIR/improve-prompt.py"

if [[ "$OSTYPE" == "msys" || "$OSTYPE" == "cygwin" || "$OS" == "Windows_NT" ]]; then
    py -3 -u "$HOOK_SCRIPT"
else
    python3 -u "$HOOK_SCRIPT"
fi

2. Update hooks/hooks.json:

{
  "type": "command",
  "command": "bash \"${CLAUDE_PLUGIN_ROOT}/scripts/run-hook.sh\"",
  "timeout": 10,
  "description": "Run the prompt improvement script"
}

This approach:

• Works on Linux/macOS natively
• Works on Windows with Git Bash (common for developers)
• Keeps a single configuration file
• Preserves your timeout and buffering improvements

The README updates documenting Windows requirements are helpful and can stay as-is.

[xobosox]

Thanks for the excellent suggestion! I've updated the code to use a bash wrapper script that detects the OS and uses the appropriate Python command (python3 on Linux/macOS, py -3 on Windows with Git Bash). This preserves cross-platform compatibility while keeping the timeout and buffering improvements.