fix(release): keep the updater configuration in the installer

Installing the previous build left an app that could not update itself: the
packaging path used to guarantee the native module build does not create the
updater configuration file, so the update client had nothing to read.

That file is now written from the single feed source and its presence in the
packaged app is checked before anything is published, so an installer that
cannot update can no longer be released.

CHANGELOG.md

@@ -13,6 +13,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Cloud-optional backup (encrypted, opt-in)
 - Plugin system for custom pipelines
 
+## [1.3.4] - 2026-09-18
+
+### Fixed
+- **Automatic updates could not start on 1.3.3**: its installer was missing the updater
+  configuration file, because the packaging path used to guarantee the native module build
+  does not create it. The file is now written from the single feed source and its presence
+  in the packaged app is verified before publishing, so an installer that cannot update is
+  never shipped.
+
 ## [1.3.3] - 2026-09-18
 
 ### Fixed