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/host_list_tab.go

@@ -83,6 +83,16 @@ func (t *HostListTab) Update(msg tea.Msg) (Tab, tea.Cmd) {
 				}
 			}
 
+		case "ctrl+k":
+			return t, func() tea.Msg {
+				return openKeyListMsg{}
+			}
+
+		case "ctrl+p":
+			return t, func() tea.Msg {
+				return openSnippetListMsg{}
+			}
+
 		case "q", "ctrl+c":
 			return t, func() tea.Msg {
 				return quitMsg{}