Adds a Claude usage tracking feature that displays session, weekly, and Sonnet usage stats. Uses the Claude CLI's /usage command to fetch data (no API key required).
Features:
- Usage popover in board header showing session, weekly, and Sonnet limits
- Progress bars with color-coded status (green/orange/red)
- Auto-refresh with configurable interval
- Caching of usage data with stale indicator
- Settings section for refresh interval configuration
Server:
- ClaudeUsageService: Executes Claude CLI via PTY (expect) to fetch usage
- New /api/claude/usage endpoint
UI:
- ClaudeUsagePopover component with usage cards
- ClaudeUsageSection in settings for configuration
- Integration with app store for persistence
