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/tui.go

@@ -81,6 +81,36 @@ func (m *Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		cmd := m.tabs.Add(tab)
 		return m, cmd
 
+	case openKeyListMsg:
+		tab := NewKeyListTab(m.dataDir)
+		cmd := m.tabs.Add(tab)
+		return m, cmd
+
+	case openSnippetListMsg:
+		tab := NewSnippetListTab(m.dataDir)
+		cmd := m.tabs.Add(tab)
+		return m, cmd
+
+	case openKeyFormMsg:
+		var tab Tab
+		if msg.editing != nil {
+			tab = NewEditKeyFormTab(msg.editing, m.dataDir)
+		} else {
+			tab = NewAddKeyFormTab(m.dataDir)
+		}
+		cmd := m.tabs.Add(tab)
+		return m, cmd
+
+	case openSnippetFormMsg:
+		var tab Tab
+		if msg.editing != nil {
+			tab = NewEditSnippetFormTab(msg.editing, m.dataDir)
+		} else {
+			tab = NewAddSnippetFormTab(m.dataDir)
+		}
+		cmd := m.tabs.Add(tab)
+		return m, cmd
+
 	case closeFormMsg:
 		if m.tabs.Len() > 1 {
 			m.tabs.CloseActive()
@@ -112,6 +142,39 @@ func (m *Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	case loadedHostsMsg:
 		m.LoadHosts(msg.hosts)
 
+	case saveKeyResultMsg:
+		if msg.err != nil {
+			m.Error = msg.err
+			return m, nil
+		}
+		// Close form tab and return to list (which auto-refreshes via Init)
+		if m.tabs.Len() > 1 {
+			m.tabs.CloseActive()
+		}
+		return m, nil
+
+	case deleteKeyResultMsg:
+		if msg.err != nil {
+			m.Error = msg.err
+		}
+		return m, nil
+
+	case saveSnippetResultMsg:
+		if msg.err != nil {
+			m.Error = msg.err
+			return m, nil
+		}
+		if m.tabs.Len() > 1 {
+			m.tabs.CloseActive()
+		}
+		return m, nil
+
+	case deleteSnippetResultMsg:
+		if msg.err != nil {
+			m.Error = msg.err
+		}
+		return m, nil
+
 	case sessionDoneMsg:
 		if msg.err != nil {
 			m.Error = msg.err