desktop/windows: ajustar NSIS (perMachine, escolher diretório, atalho) e mover store para AppData

- tauri.conf.json: configura nsis (installMode perMachine, allowToChangeInstallDirectory, installDirName, createDesktopShortcut)
- main.tsx: Store.load agora usa appLocalDataDir (dados do app em AppData do usuário)
- README: documenta instalação Windows, dados em AppData e build leve (--bundles nsis)

apps/desktop/src/main.tsx

@@ -3,6 +3,7 @@ import { useCallback, useEffect, useMemo, useRef, useState } from "react"
 import { createRoot } from "react-dom/client"
 import { invoke } from "@tauri-apps/api/core"
 import { Store } from "@tauri-apps/plugin-store"
+import { appLocalDataDir } from "@tauri-apps/api/path"
 import { ExternalLink, Eye, EyeOff, GalleryVerticalEnd, Loader2, RefreshCw } from "lucide-react"
 import { Tabs, TabsContent, TabsList, TabsTrigger } from "./components/ui/tabs"
 import { cn } from "./lib/utils"
@@ -103,7 +104,8 @@ const appUrl = normalizeUrl(import.meta.env.VITE_APP_URL, DEFAULT_APP_URL)
 const apiBaseUrl = normalizeUrl(import.meta.env.VITE_API_BASE_URL, appUrl)
 
 async function loadStore(): Promise<Store> {
-  return await Store.load(STORE_FILENAME)
+  const dir = await appLocalDataDir()
+  return await Store.load(STORE_FILENAME, { dir })
 }
 
 async function readToken(store: Store): Promise<string | null> {