refactor: migrate Charm libraries to v2

Import paths moved to charm.land/*/v2 and the v1 paths no longer resolve.
Ports View() -> tea.View, AltScreen/MouseMode to View fields, KeyPressMsg,
and the new progress/viewport constructors. Styled output outside Bubble
Tea switched to lipgloss.Print* because v2 downsamples colour at the output
layer. vendorHash refreshed.

internal/sarin/stop.go

@@ -6,7 +6,7 @@ import (
 	"sync"
 	"sync/atomic"
 
-	tea "github.com/charmbracelet/bubbletea"
+	tea "charm.land/bubbletea/v2"
 )
 
 const forceExitCode = 130