feat: implement basic TUI framework with host list

- Add Bubble Tea TUI model with Init/Update/View
- Implement host list screen with keyboard navigation (up/down/enter/q)
- Add styled rendering for hosts, selection, tags
- Create hostkeeper tui CLI command
- Add tests for TUI initialization and host loading
- Update project state documentation

pkg/tui/tui.go

@@ -0,0 +1,101 @@
+package tui
+
+import (
+	tea "github.com/charmbracelet/bubbletea"
+	"github.com/charmbracelet/lipgloss"
+
+	"git.tukangketik.id/swanadiva/hostkeeper/internal/models"
+)
+
+// Styles for TUI components
+var (
+	TitleStyle     = lipgloss.NewStyle().Foreground(lipgloss.Color("86")).Bold(true)
+	SubtitleStyle  = lipgloss.NewStyle().Foreground(lipgloss.Color("241"))
+	HighlightStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("212")).Bold(true)
+	ErrorStyle     = lipgloss.NewStyle().Foreground(lipgloss.Color("196")).Bold(true)
+	SuccessStyle   = lipgloss.NewStyle().Foreground(lipgloss.Color("76")).Bold(true)
+	InfoStyle      = lipgloss.NewStyle().Foreground(lipgloss.Color("117"))
+)
+
+// Screen represents different TUI screens
+type Screen int
+
+const (
+	ScreenHostList Screen = iota
+	ScreenConnection
+	ScreenSettings
+)
+
+// Model represents the main TUI model
+type Model struct {
+	CurrentScreen Screen
+	Hosts         []*models.Host
+	SelectedIndex int
+	Error         error
+	Quit          bool
+}
+
+// New creates a new TUI model
+func New() *Model {
+	return &Model{
+		CurrentScreen: ScreenHostList,
+		SelectedIndex: 0,
+		Quit:          false,
+	}
+}
+
+// Init initializes the TUI
+func (m *Model) Init() tea.Cmd {
+	return nil
+}
+
+// Update handles messages and updates the model
+func (m *Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		switch msg.String() {
+		case "ctrl+c", "q":
+			m.Quit = true
+			return m, tea.Quit
+
+		case "up", "k":
+			if m.SelectedIndex > 0 {
+				m.SelectedIndex--
+			}
+
+		case "down", "j":
+			if m.SelectedIndex < len(m.Hosts)-1 {
+				m.SelectedIndex++
+			}
+
+		case "enter", " ":
+			if len(m.Hosts) > 0 {
+				return m, tea.Quit
+			}
+		}
+	}
+
+	return m, nil
+}
+
+// View renders the TUI
+func (m *Model) View() string {
+	if m.Quit {
+		return "Thanks for using hostkeeper!\n"
+	}
+
+	switch m.CurrentScreen {
+	case ScreenHostList:
+		return renderHostList(m)
+	default:
+		return "Screen not implemented yet"
+	}
+}
+
+// LoadHosts loads hosts into the TUI model
+func (m *Model) LoadHosts(hosts []*models.Host) {
+	m.Hosts = hosts
+	if len(hosts) > 0 && m.SelectedIndex >= len(hosts) {
+		m.SelectedIndex = len(hosts) - 1
+	}
+}