refactor(tui): move to Bubble Tea, Lip Gloss and Bubbles v2

Switch imports to the charm.land v2 modules. Return tea.View from Model.View,
set alt screen and window title there, use KeyPressMsg and the "space" key
name, and call SetWidth on text inputs.

internal/tui/styles.go

@@ -4,7 +4,7 @@ package tui
 import (
 	"strings"
 
-	"github.com/charmbracelet/lipgloss"
+	"charm.land/lipgloss/v2"
 )
 
 // Colors - matching kportal style, optimized for dark terminals