Create dashboard view with printer overview

[krjordan]

Implement main dashboard showing all printers at a glance.

Requirements

• Grid/list layout showing all printers
• Compact printer status cards
• Visual status indicators (colors/icons)
• Auto-refresh with smooth updates
• Responsive to terminal size

Acceptance Criteria

• Shows all configured printers
• Each printer card shows: name, status, progress
• Color coding: green (idle), blue (printing), red (error)
• Refreshes every second without flicker
• Handles 10+ printers efficiently
• Click/Enter to view printer details