bump version to 1.2.0

- Update pyproject.toml version to 1.2.0
- Update updater.py CURRENT_VERSION to 1.2.0
- Prepare for release with Messages display feature

Release v1.0.0

🎯 Features:
- Real-time token usage monitoring in Claude Code status bar
- Cost tracking with USD display
- Session reset timer with countdown
- Color-coded usage indicators (green/yellow/red)
- One-line installation script with auto-configuration
- PyPI package distribution
- Multiple installation methods (pip, uv, pipx)
- Shell aliases (cs, cstatus)
- tmux and zsh integration support

🚀 Installation:
curl -fsSL https://raw.githubusercontent.com/leeguooooo/claude-code-usage-bar/main/web-install.sh | bash

📦 Package:
https://pypi.org/project/claude-statusbar/