feat: TUI Key & Snippet Management - Task 19

- KeyListTab: view/add/edit/delete SSH keys (Ctrl+K from host list)
- KeyFormTab: add/edit key form with name, type, private key, passphrase
- SnippetListTab: view/add/edit/delete snippets (Ctrl+P from host list)
- SnippetFormTab: add/edit snippet form with name, command, description, tags
- Updated status bar with new hints
- Save/delete commands for both key pairs and snippets

pkg/tui/key_list_tab.go

@@ -0,0 +1,192 @@
+package tui
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"sync"
+
+	tea "github.com/charmbracelet/bubbletea"
+
+	"git.tukangketik.id/swanadiva/hostkeeper/internal/models"
+	"git.tukangketik.id/swanadiva/hostkeeper/pkg/storage"
+)
+
+type keyListState int
+
+const (
+	keyListLoading keyListState = iota
+	keyListReady
+	keyListError
+)
+
+// KeyListTab displays and manages SSH key pairs
+type KeyListTab struct {
+	dataDir string
+	keys    []*models.KeyPair
+	selected int
+	state    keyListState
+	err      error
+	width    int
+	height   int
+	mu       sync.Mutex
+}
+
+func NewKeyListTab(dataDir string) *KeyListTab {
+	return &KeyListTab{
+		dataDir: dataDir,
+		state:   keyListLoading,
+	}
+}
+
+func (t *KeyListTab) Name() string { return "SSH Keys" }
+
+func (t *KeyListTab) Init() tea.Cmd {
+	return func() tea.Msg {
+		store, err := storage.NewJSONStorage(t.dataDir)
+		if err != nil {
+			return keyListLoadedMsg{err: err}
+		}
+		keys, err := store.ListKeyPairs(context.Background())
+		if err != nil {
+			return keyListLoadedMsg{err: err}
+		}
+		return keyListLoadedMsg{keys: keys}
+	}
+}
+
+func (t *KeyListTab) Update(msg tea.Msg) (Tab, tea.Cmd) {
+	switch msg := msg.(type) {
+	case tea.WindowSizeMsg:
+		t.mu.Lock()
+		t.width = msg.Width
+		t.height = msg.Height
+		t.mu.Unlock()
+
+	case keyListLoadedMsg:
+		t.mu.Lock()
+		if msg.err != nil {
+			t.state = keyListError
+			t.err = msg.err
+		} else {
+			t.state = keyListReady
+			t.keys = msg.keys
+		}
+		t.mu.Unlock()
+
+	case saveKeyResultMsg:
+		return t, t.Init()
+
+	case deleteKeyResultMsg:
+		if msg.err != nil {
+			t.mu.Lock()
+			t.err = msg.err
+			t.mu.Unlock()
+		}
+		return t, t.Init()
+
+	case tea.KeyMsg:
+		switch msg.String() {
+		case "up", "k":
+			t.mu.Lock()
+			if t.selected > 0 {
+				t.selected--
+			}
+			t.mu.Unlock()
+
+		case "down", "j":
+			t.mu.Lock()
+			if t.selected < len(t.keys)-1 {
+				t.selected++
+			}
+			t.mu.Unlock()
+
+		case "ctrl+n":
+			return t, func() tea.Msg { return openKeyFormMsg{} }
+
+		case "ctrl+e":
+			t.mu.Lock()
+			keys := t.keys
+			idx := t.selected
+			t.mu.Unlock()
+			if len(keys) > 0 && idx >= 0 && idx < len(keys) {
+				return t, func() tea.Msg { return openKeyFormMsg{editing: keys[idx]} }
+			}
+
+		case "delete", "d":
+			t.mu.Lock()
+			keys := t.keys
+			idx := t.selected
+			t.mu.Unlock()
+			if len(keys) > 0 && idx >= 0 && idx < len(keys) {
+				return t, deleteKeyCmd(keys[idx].ID, t.dataDir)
+			}
+
+		case "esc":
+			return t, func() tea.Msg { return closeFormMsg{} }
+		}
+	}
+
+	return t, nil
+}
+
+func (t *KeyListTab) View() string {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	var b strings.Builder
+
+	b.WriteString(AppTitleStyle.Render("SSH Key Pairs"))
+	b.WriteString("\n\n")
+
+	switch t.state {
+	case keyListLoading:
+		b.WriteString(SubtitleStyle.Render("Loading keys..."))
+		return b.String()
+	case keyListError:
+		b.WriteString(ErrorStyle.Render(fmt.Sprintf("Error: %v", t.err)))
+		b.WriteString("\n\n")
+		b.WriteString(SubtitleStyle.Render("Press Esc to go back"))
+		return b.String()
+	}
+
+	if t.err != nil {
+		b.WriteString(ErrorStyle.Render(fmt.Sprintf("Error: %v", t.err)))
+		b.WriteString("\n\n")
+	}
+
+	if len(t.keys) == 0 {
+		b.WriteString(SubtitleStyle.Render("No SSH keys stored."))
+		b.WriteString("\n")
+		b.WriteString(SubtitleStyle.Render("Press Ctrl+N to add a new key."))
+	} else {
+		for i, key := range t.keys {
+			var line string
+			if key.Type != "" {
+				line = fmt.Sprintf("  %s  (%s)", key.Name, key.Type)
+			} else {
+				line = fmt.Sprintf("  %s", key.Name)
+			}
+
+			if i == t.selected {
+				b.WriteString(SelectedStyle.Render(line))
+			} else {
+				b.WriteString(HostNameStyle.Render(line))
+			}
+			b.WriteString("\n")
+		}
+	}
+
+	b.WriteString("\n")
+	b.WriteString(SubtitleStyle.Render("Ctrl+N:add  Ctrl+E:edit  D:delete  Esc:back"))
+
+	return b.String()
+}
+
+func (t *KeyListTab) Close() {}
+
+// keyListLoadedMsg carries the loaded key list
+type keyListLoadedMsg struct {
+	keys []*models.KeyPair
+	err  error
+}