improvement(updates): validate update path and fix native mac help (#6580)

* Desktop update check

* Update script

Author: Sg312

apps/desktop/README.md

@@ -35,6 +35,7 @@ src/main/           # main process (bundled to dist/main.cjs)
   browser-sites/    # imported site directory, safeStorage at rest
   browser-import/   # one-shot import of profiles, cookies and passwords
 src/preload/        # contextBridge IPC bridge (bundled to dist/preload.cjs)
+native/             # Node-API/AppKit bridge for native macOS Help docs search
 static/             # bundled local pages (offline.html)
 e2e/                # Playwright _electron smoke suite
 ```

apps/desktop/electron-builder.yml

@@ -13,11 +13,12 @@ files:
 
 asar: true
 
-# Native modules cannot be dlopen'd from inside an asar.
-# `scripts/ensure-pty-prebuilds.ts` guarantees both arch prebuilds are present
-# before packaging; see mac.x64ArchFiles for how the universal merge treats them.
+# Native modules cannot be dlopen'd from inside an asar. The Help-search addon
+# is already universal; `scripts/ensure-pty-prebuilds.ts` guarantees both pty
+# prebuilds are present before packaging.
 asarUnpack:
   - "**/node_modules/@lydell/node-pty-*/prebuilds/**"
+  - "**/dist/native/*.node"
 
 # Space-free regardless of productName ("Sim Dev" etc.): GitHub rewrites
 # asset names containing spaces, which would desync the electron-updater