Redo connection manager: Stacks, More options, drag & drop, WinSCP import

Folders become Stacks (connections.json v2, no v1 migration): collapsible
stack-first list, open-stack-in-tabs (first reuses a pristine tab), drag
connections between stacks. More... reveals a per-connection Local
directory applied to the other panel when local and untouched. Import
reads a WinSCP.ini export incl. deobfuscated passwords.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/bun/menu.ts

@@ -11,21 +11,21 @@ import type { ConnectionStore } from "./store/connections";
 export async function applyApplicationMenu(store: ConnectionStore): Promise<void> {
 	if (process.platform !== "darwin") return;
 
-	const { folders, connections } = await store.load();
+	const { stacks, connections } = await store.load();
 	const item = (c: SavedConnection): ApplicationMenuItemConfig => ({
 		label: c.name,
 		action: `connect:${c.id}`,
 	});
-	const rootItems = connections.filter((c) => !c.folderId).map(item);
-	const folderMenus: ApplicationMenuItemConfig[] = folders.map((folder) => ({
-		label: folder.name,
-		submenu: connections.filter((c) => c.folderId === folder.id).map(item),
+	const looseItems = connections.filter((c) => !c.stackId).map(item);
+	const stackMenus: ApplicationMenuItemConfig[] = stacks.map((stack) => ({
+		label: stack.name,
+		submenu: connections.filter((c) => c.stackId === stack.id).map(item),
 	}));
 
 	const connectSubmenu: ApplicationMenuItemConfig[] = [
-		...rootItems,
-		...folderMenus,
-		...(rootItems.length || folderMenus.length ? [{ type: "separator" } as const] : []),
+		...looseItems,
+		...stackMenus,
+		...(looseItems.length || stackMenus.length ? [{ type: "separator" } as const] : []),
 		{ label: "Connection Manager…", action: "manage-connections" },
 	];