chore(release): v1.4.0

Shortcuts gain several bindings per action, mouse buttons and a searchable
picker, and the stored shortcut schema changes shape, so this is a minor bump.
Existing shortcuts migrate on first launch.

Play release notes state that this release carries no mobile feature changes;
the work is desktop-only.

apps/desktop/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@d3ro/desktop",
-  "version": "1.3.7",
+  "version": "1.4.0",
   "productName": "d3ro-voice",
   "description": "로컬 AI 음성 어시스턴트 (Electron)",
   "main": "./out/main/index.js",