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/rpc-handlers.ts

@@ -8,6 +8,7 @@ import { SftpProvider } from "./fs/sftp";
 import type { ConnectionStore } from "./store/connections";
 import type { SettingsStore } from "./store/settings";
 import { loadSshConfigHosts } from "./store/ssh-config";
+import { importWinScpIni } from "./store/winscp-import";
 import type { TransferEngine } from "./transfers/engine";
 import { removeRecursive } from "./transfers/walk";
 
@@ -152,20 +153,39 @@ export function createAppRPC({
 						return {};
 					}),
 
-				upsertFolder: ({ folder }) =>
+				upsertStack: ({ stack }) =>
 					wrap(async () => {
-						const id = await store.upsertFolder(folder);
+						const id = await store.upsertStack(stack);
 						events.connectionsChanged();
 						return { id };
 					}),
 
-				deleteFolder: ({ id }) =>
+				deleteStack: ({ id }) =>
 					wrap(async () => {
-						await store.deleteFolder(id);
+						await store.deleteStack(id);
 						events.connectionsChanged();
 						return {};
 					}),
 
+				importWinScp: () =>
+					wrap(async () => {
+						const { homedir } = await import("node:os");
+						const picked = await Utils.openFileDialog({
+							startingFolder: homedir(),
+							allowedFileTypes: "*",
+							canChooseFiles: true,
+							canChooseDirectory: false,
+							allowsMultipleSelection: false,
+						});
+						const file = picked.find((p) => p.trim().length > 0);
+						// dialog cancelled — all-zero result, UI shows nothing
+						if (!file) return { connections: 0, stacks: 0, skipped: 0 };
+						const text = await (await import("node:fs/promises")).readFile(file, "utf8");
+						const result = await importWinScpIni(text, store);
+						events.connectionsChanged();
+						return result;
+					}),
+
 				getSshConfigHosts: () => wrap(async () => ({ hosts: loadSshConfigHosts() })),
 
 				// ---- settings ----