Release v0.1.0

Phase 1 Achievements

Core Shell

• Electron window with native controls and menu bar
• File tree with virtual scrolling (react-window)
• Status bar with file info
• Folder selection (native dialog)
• Basic .feature file loading
• Keyboard shortcuts (⌘B, ⌘O)
• Design tokens and spacing grid
• Startup time: 344ms (< 500ms target)