perf(desktop): load node-pty when an interactive WSL install starts

wsl/runtime.ts imported the native @lydell/node-pty addon at module
level, and the WSL layer imports that module during startup on Windows,
so every launch loaded the addon DLL before the window was created even
though only the interactive install commands use it. Import it inside
runInteractiveCommand instead.

packages/desktop/src/main/wsl/runtime.ts

@@ -1,5 +1,4 @@
 import { spawn } from "node:child_process"
-import * as pty from "@lydell/node-pty"
 import type { WslDistroProbe, WslInstalledDistro, WslOnlineDistro, WslRuntimeCheck } from "@opencode/app/wsl/types"
 import { Effect, FileSystem, Path } from "effect"
 import { nativeT } from "../native/translations"
@@ -117,7 +116,14 @@ function runCommand(command: string, args: string[], opts: RunWslOptions = {}) {
   })
 }
 
-function runInteractiveCommand(command: string, args: string[], opts: RunWslOptions = {}, defaultTimeoutMs: number) {
+async function runInteractiveCommand(
+  command: string,
+  args: string[],
+  opts: RunWslOptions = {},
+  defaultTimeoutMs: number,
+) {
+  // The native addon is only needed for interactive installs; loading it here keeps it out of startup.
+  const pty = await import("@lydell/node-pty")
   return new Promise<WslCommandResult>((resolve, reject) => {
     const child = pty.spawn(command, args, {
       name: "xterm-color",