feat: upgrade to bubbletea v2, bubbles v2, lipgloss v2

Migrate to charm.land/bubbletea/v2 (RC2), charm.land/bubbles/v2 (RC1),
and charm.land/lipgloss/v2 (beta3).

Breaking API changes addressed:
- Import paths: github.com/charmbracelet/* -> charm.land/*/v2
- Root View() returns tea.View with AltScreen declared, sub-models
  keep returning string via game.Gamer interface
- lipgloss.AdaptiveColor -> compat.AdaptiveColor with lipgloss.Color()
  wrapped values for v2 color.Color interface compliance
- lipgloss.TerminalColor -> compat.AdaptiveColor (nonogram)
- viewport.New() now uses functional options (WithWidth/WithHeight)
- viewport Width/Height fields -> SetWidth()/SetHeight() methods
- tea.KeyMsg -> tea.KeyPressMsg in tests, Key struct fields changed
- WithAltScreen() program option -> declarative v.AltScreen in View()

When charmbracelet releases stable v2, update go.mod versions from
RC/beta to stable -- no code changes expected.

commit

4603a9566fa77edbd52d5042580bc759bd632cb8

parent

0cd14ad12c4221dbf67ca4be65481aa36bd1bcf3

author

Dami <dami.etoile@gmail.com>