Refactor Windows instance directory retrieval in deeplink handling

- Updated the `getInstanceDir` function to use `os.homedir()` as a fallback for the local app data path, ensuring compatibility across different Windows environments.
- Improved code clarity by consolidating the logic for determining the local application data directory.

src/desktop/deeplink-ipc.js

@@ -6,6 +6,7 @@ import {
   writeFileSync
 } from 'node:fs'
 import net from 'node:net'
+import os from 'node:os'
 import { join } from 'node:path'
 
 export const PROTOCOL_PREFIX = 'farmcontrol://'
@@ -18,11 +19,10 @@ const PIPE_RETRY_DELAY_MS = 100
 
 export function getInstanceDir() {
   if (process.platform === 'win32') {
-    const localAppData = process.env.LOCALAPPDATA || process.env.APPDATA
-    if (localAppData) {
+    const localAppData =
+      process.env.LOCALAPPDATA || join(os.homedir(), 'AppData', 'Local')
     return join(localAppData, 'com.tombutcher.farmcontrol', 'instance')
   }
-  }
 
   return join(process.env.TMPDIR || '/tmp', 'com.tombutcher.farmcontrol', 'instance')
 }