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/host_list.go

@@ -0,0 +1,84 @@
+package tui
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/charmbracelet/lipgloss"
+
+	"git.tukangketik.id/swanadiva/hostkeeper/internal/models"
+)
+
+var (
+	HostNameStyle   = lipgloss.NewStyle().Foreground(lipgloss.Color("226")).Bold(true)
+	HostDetailStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("245"))
+	SelectedStyle   = lipgloss.NewStyle().Foreground(lipgloss.Color("212")).Background(lipgloss.Color("235")).Padding(0, 1)
+	TagStyle        = lipgloss.NewStyle().Foreground(lipgloss.Color("86"))
+)
+
+// renderHostList renders the host list screen
+func renderHostList(m *Model) string {
+	var b strings.Builder
+
+	b.WriteString(TitleStyle.Render("HOSTKEEPER - SSH Manager"))
+	b.WriteString("\n\n")
+
+	if len(m.Hosts) == 0 {
+		b.WriteString(SubtitleStyle.Render("No hosts found. Add your first host with: hostkeeper add"))
+		b.WriteString("\n\n")
+		b.WriteString(InfoStyle.Render("Press 'q' to quit"))
+		return b.String()
+	}
+
+	for i, host := range m.Hosts {
+		if i == m.SelectedIndex {
+			b.WriteString(renderSelectedHost(host))
+		} else {
+			b.WriteString(renderHost(host))
+		}
+		b.WriteString("\n")
+	}
+
+	b.WriteString("\n")
+	b.WriteString(SubtitleStyle.Render("\u2191\u2193: Navigate | Enter: Connect | q: Quit"))
+
+	return b.String()
+}
+
+// renderHost renders a single host
+func renderHost(host *models.Host) string {
+	var b strings.Builder
+
+	b.WriteString(HostNameStyle.Render(host.Name))
+	b.WriteString("\n")
+
+	details := fmt.Sprintf("   %s@%s:%d", host.Username, host.Hostname, host.Port)
+	b.WriteString(HostDetailStyle.Render(details))
+
+	if len(host.Tags) > 0 {
+		tags := formatTagsForTUI(host.Tags)
+		b.WriteString(" " + TagStyle.Render(tags))
+	}
+
+	return b.String()
+}
+
+// renderSelectedHost renders the selected host with highlight
+func renderSelectedHost(host *models.Host) string {
+	hostText := renderHost(host)
+	return SelectedStyle.Render(hostText)
+}
+
+// formatTagsForTUI formats tags for TUI display
+func formatTagsForTUI(tags []string) string {
+	if len(tags) == 0 {
+		return ""
+	}
+
+	var formatted []string
+	for _, tag := range tags {
+		formatted = append(formatted, "["+tag+"]")
+	}
+
+	return strings.Join(formatted, " ")
+}

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
+	}
+}

pkg/tui/tui_test.go

@@ -0,0 +1,32 @@
+package tui
+
+import (
+	"testing"
+)
+
+func TestTUIInitialization(t *testing.T) {
+	ui := New()
+	if ui == nil {
+		t.Fatal("Failed to initialize TUI")
+	}
+
+	if ui.CurrentScreen != ScreenHostList {
+		t.Errorf("expected CurrentScreen ScreenHostList, got %d", ui.CurrentScreen)
+	}
+
+	if ui.Quit {
+		t.Error("expected Quit to be false")
+	}
+}
+
+func TestTUILoadHosts(t *testing.T) {
+	ui := New()
+	if ui == nil {
+		t.Fatal("Failed to initialize TUI")
+	}
+
+	ui.LoadHosts(nil)
+	if ui.Hosts != nil {
+		t.Error("expected Hosts to be nil")
+	}
+}