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/snippet_list_tab.go

@@ -0,0 +1,193 @@
+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 snippetListState int
+
+const (
+	snippetListLoading snippetListState = iota
+	snippetListReady
+	snippetListError
+)
+
+// SnippetListTab displays and manages command snippets
+type SnippetListTab struct {
+	dataDir  string
+	snippets []*models.Snippet
+	selected int
+	state    snippetListState
+	err      error
+	width    int
+	height   int
+	mu       sync.Mutex
+}
+
+func NewSnippetListTab(dataDir string) *SnippetListTab {
+	return &SnippetListTab{
+		dataDir: dataDir,
+		state:   snippetListLoading,
+	}
+}
+
+func (t *SnippetListTab) Name() string { return "Snippets" }
+
+func (t *SnippetListTab) Init() tea.Cmd {
+	return func() tea.Msg {
+		store, err := storage.NewJSONStorage(t.dataDir)
+		if err != nil {
+			return snippetListLoadedMsg{err: err}
+		}
+		snippets, err := store.ListSnippets(context.Background())
+		if err != nil {
+			return snippetListLoadedMsg{err: err}
+		}
+		return snippetListLoadedMsg{snippets: snippets}
+	}
+}
+
+func (t *SnippetListTab) 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 snippetListLoadedMsg:
+		t.mu.Lock()
+		if msg.err != nil {
+			t.state = snippetListError
+			t.err = msg.err
+		} else {
+			t.state = snippetListReady
+			t.snippets = msg.snippets
+		}
+		t.mu.Unlock()
+
+	case saveSnippetResultMsg:
+		return t, t.Init()
+
+	case deleteSnippetResultMsg:
+		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.snippets)-1 {
+				t.selected++
+			}
+			t.mu.Unlock()
+
+		case "ctrl+n":
+			return t, func() tea.Msg { return openSnippetFormMsg{} }
+
+		case "ctrl+e":
+			t.mu.Lock()
+			snippets := t.snippets
+			idx := t.selected
+			t.mu.Unlock()
+			if len(snippets) > 0 && idx >= 0 && idx < len(snippets) {
+				return t, func() tea.Msg { return openSnippetFormMsg{editing: snippets[idx]} }
+			}
+
+		case "delete", "d":
+			t.mu.Lock()
+			snippets := t.snippets
+			idx := t.selected
+			t.mu.Unlock()
+			if len(snippets) > 0 && idx >= 0 && idx < len(snippets) {
+				return t, deleteSnippetCmd(snippets[idx].ID, t.dataDir)
+			}
+
+		case "esc":
+			return t, func() tea.Msg { return closeFormMsg{} }
+		}
+	}
+
+	return t, nil
+}
+
+func (t *SnippetListTab) View() string {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	var b strings.Builder
+
+	b.WriteString(AppTitleStyle.Render("Command Snippets"))
+	b.WriteString("\n\n")
+
+	switch t.state {
+	case snippetListLoading:
+		b.WriteString(SubtitleStyle.Render("Loading snippets..."))
+		return b.String()
+	case snippetListError:
+		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.snippets) == 0 {
+		b.WriteString(SubtitleStyle.Render("No snippets stored."))
+		b.WriteString("\n")
+		b.WriteString(SubtitleStyle.Render("Press Ctrl+N to add a new snippet."))
+	} else {
+		for i, sn := range t.snippets {
+			var line string
+			desc := sn.Description
+			if desc != "" {
+				line = fmt.Sprintf("  %s  — %s", sn.Name, desc)
+			} else {
+				line = fmt.Sprintf("  %s", sn.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 *SnippetListTab) Close() {}
+
+// snippetListLoadedMsg carries the loaded snippet list
+type snippetListLoadedMsg struct {
+	snippets []*models.Snippet
+	err      error
+}