Bump version to 1.5.0 (release candidate)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: jonberenguer

package-lock.json

@@ -2,7 +2,7 @@
   "name": "moments-app",
   "productName": "Moments",
   "private": true,
-  "version": "1.2.1",
+  "version": "1.5.0",
   "type": "commonjs",
   "description": "Photo & video slideshow editor with GPU-accelerated export",
   "homepage": "https://localhost",