tui: show real-time MCP server status on home screen with connection indicators
tui: create dedicated logo component and improve home screen layout
tui: make session layout responsive with sidebar visible on wide terminals
- Displays MCP servers with visual status indicators (connected/failed/disabled)
- Shows error messages for failed connections to help users troubleshoot
- Replaces static help text with dynamic keybind display that updates based on user config
- Adds weather and puppeteer MCP servers to example configuration
