Merge pull request #265 from afonsojramos/gate-flatpak-snap-macos

Reviewed: clean platform detection refactor, no audio code touched, all gates correct. Lockfiles will be regenerated post-merge.

package.json

@@ -31,6 +31,7 @@
     "@tauri-apps/plugin-clipboard-manager": "^2",
     "@tauri-apps/plugin-dialog": "^2.5.0",
     "@tauri-apps/plugin-opener": "^2",
+    "@tauri-apps/plugin-os": "^2",
     "lucide-svelte": "^1.0.1",
     "svelte-i18n": "^4.0.0"
   },