chore: add package.json with deploy script

Fix npm run deploy using parent package.json due to missing local package.json.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package.json

@@ -0,0 +1,8 @@
+{
+    "name": "posimai-store",
+    "version": "1.0.0",
+    "private": true,
+    "scripts": {
+        "deploy": "git push gitea main && git push github main"
+    }
+}