feat(desktop-client): split autostart and keep-alive per platform

Refactors openAtLogin and keepRunningInBackground to make the macOS/Windows
divergence explicit instead of leaning on Electron's cross-platform
abstraction:

- openAtLogin on Windows now passes path: process.execPath and args: []
  so the registry HKCU Run key always points at the right binary.
- keepRunningInBackground on Windows shows a one-shot tray balloon ("省心
  推已最小化到托盘…") so first-time users notice the app is still alive;
  persisted via a private hasShownBackgroundBalloon flag so it never fires
  again. macOS preserves the dock icon and stays silent.
- Sets AppUserModelID early on Windows so tray.displayBalloon's Win10+
  Toast routing actually fires.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/desktop-client/src/main/app-settings.ts

@@ -10,46 +10,81 @@ export interface DesktopAppSettings {
 
 export type DesktopAppSettingKey = keyof DesktopAppSettings
 
+interface DesktopAppInternalFlags {
+  hasShownBackgroundBalloon: boolean
+}
+
 const DEFAULT_DESKTOP_APP_SETTINGS: DesktopAppSettings = {
   openAtLogin: false,
   keepRunningInBackground: true,
 }
 
+const DEFAULT_INTERNAL_FLAGS: DesktopAppInternalFlags = {
+  hasShownBackgroundBalloon: false,
+}
+
 let cachedSettings: DesktopAppSettings = { ...DEFAULT_DESKTOP_APP_SETTINGS }
+let cachedFlags: DesktopAppInternalFlags = { ...DEFAULT_INTERNAL_FLAGS }
 
 function settingsPath(): string {
   return join(app.getPath('userData'), 'desktop-settings.json')
 }
 
-function normalizeSettings(input: unknown): DesktopAppSettings {
+function normalizePersistedFile(input: unknown): {
+  settings: DesktopAppSettings
+  flags: DesktopAppInternalFlags
+} {
   if (!input || typeof input !== 'object') {
-    return { ...DEFAULT_DESKTOP_APP_SETTINGS }
+    return {
+      settings: { ...DEFAULT_DESKTOP_APP_SETTINGS },
+      flags: { ...DEFAULT_INTERNAL_FLAGS },
+    }
   }
 
-  const candidate = input as Partial<Record<DesktopAppSettingKey, unknown>>
+  const candidate = input as Partial<
+    Record<DesktopAppSettingKey | keyof DesktopAppInternalFlags, unknown>
+  >
   return {
-    openAtLogin:
-      typeof candidate.openAtLogin === 'boolean'
-        ? candidate.openAtLogin
-        : DEFAULT_DESKTOP_APP_SETTINGS.openAtLogin,
-    keepRunningInBackground:
-      typeof candidate.keepRunningInBackground === 'boolean'
-        ? candidate.keepRunningInBackground
-        : DEFAULT_DESKTOP_APP_SETTINGS.keepRunningInBackground,
+    settings: {
+      openAtLogin:
+        typeof candidate.openAtLogin === 'boolean'
+          ? candidate.openAtLogin
+          : DEFAULT_DESKTOP_APP_SETTINGS.openAtLogin,
+      keepRunningInBackground:
+        typeof candidate.keepRunningInBackground === 'boolean'
+          ? candidate.keepRunningInBackground
+          : DEFAULT_DESKTOP_APP_SETTINGS.keepRunningInBackground,
+    },
+    flags: {
+      hasShownBackgroundBalloon:
+        typeof candidate.hasShownBackgroundBalloon === 'boolean'
+          ? candidate.hasShownBackgroundBalloon
+          : DEFAULT_INTERNAL_FLAGS.hasShownBackgroundBalloon,
+    },
   }
 }
 
-function readPersistedSettings(): DesktopAppSettings {
+function readPersistedFile(): {
+  settings: DesktopAppSettings
+  flags: DesktopAppInternalFlags
+} {
   try {
-    return normalizeSettings(JSON.parse(readFileSync(settingsPath(), 'utf8')))
+    return normalizePersistedFile(JSON.parse(readFileSync(settingsPath(), 'utf8')))
   } catch {
-    return { ...DEFAULT_DESKTOP_APP_SETTINGS }
+    return {
+      settings: { ...DEFAULT_DESKTOP_APP_SETTINGS },
+      flags: { ...DEFAULT_INTERNAL_FLAGS },
+    }
   }
 }
 
-function persistSettings(settings: DesktopAppSettings): void {
+function persistFile(): void {
   try {
-    writeFileSync(settingsPath(), JSON.stringify(settings), 'utf8')
+    writeFileSync(
+      settingsPath(),
+      JSON.stringify({ ...cachedSettings, ...cachedFlags }),
+      'utf8',
+    )
   } catch (error) {
     console.warn('[desktop-settings] persist failed', error)
   }
@@ -64,12 +99,38 @@ function readSystemOpenAtLogin(fallback: boolean): boolean {
   }
 }
 
+// Platform-specific login-item application.
+//
+// macOS — `setLoginItemSettings({ openAtLogin })` registers a LaunchAgent via
+// the ServiceManagement framework. `path`/`args` are ignored on darwin; the
+// system always launches the bundled .app. We keep `openAsHidden: false`
+// because the user wants the main window to appear at login.
+//
+// Windows — `setLoginItemSettings` writes to
+// `HKCU\Software\Microsoft\Windows\CurrentVersion\Run`. In dev the registry
+// would point at electron.exe, so we explicitly pass `path: process.execPath`
+// and an empty `args: []` so the production NSIS-installed exe is registered
+// correctly. No `--hidden` flag because the user wants a normal window at
+// startup.
+//
+// Linux — `setLoginItemSettings` is a no-op in Electron; we silently accept
+// the value but the OS will not honor it.
 function applyOpenAtLogin(openAtLogin: boolean): boolean {
   try {
-    app.setLoginItemSettings({
-      openAtLogin,
-      openAsHidden: false,
-    })
+    if (process.platform === 'darwin') {
+      app.setLoginItemSettings({
+        openAtLogin,
+        openAsHidden: false,
+      })
+    } else if (process.platform === 'win32') {
+      app.setLoginItemSettings({
+        openAtLogin,
+        path: process.execPath,
+        args: [],
+      })
+    } else {
+      app.setLoginItemSettings({ openAtLogin })
+    }
     return readSystemOpenAtLogin(openAtLogin)
   } catch (error) {
     console.warn('[desktop-settings] apply login item failed', error)
@@ -78,12 +139,13 @@ function applyOpenAtLogin(openAtLogin: boolean): boolean {
 }
 
 export function initDesktopAppSettings(): DesktopAppSettings {
-  cachedSettings = readPersistedSettings()
+  const { settings, flags } = readPersistedFile()
   cachedSettings = {
-    ...cachedSettings,
-    openAtLogin: applyOpenAtLogin(cachedSettings.openAtLogin),
+    ...settings,
+    openAtLogin: applyOpenAtLogin(settings.openAtLogin),
   }
-  persistSettings(cachedSettings)
+  cachedFlags = flags
+  persistFile()
   return getDesktopAppSettings()
 }
 
@@ -109,6 +171,18 @@ export function setDesktopAppSetting(
   }
 
   cachedSettings = next
-  persistSettings(cachedSettings)
+  persistFile()
   return getDesktopAppSettings()
 }
+
+export function hasShownBackgroundBalloon(): boolean {
+  return cachedFlags.hasShownBackgroundBalloon
+}
+
+export function markBackgroundBalloonShown(): void {
+  if (cachedFlags.hasShownBackgroundBalloon) {
+    return
+  }
+  cachedFlags = { ...cachedFlags, hasShownBackgroundBalloon: true }
+  persistFile()
+}