fix: fall back to Locale.ROOT when no i18n_en.properties exists for English locale

[busehalis-sap]

Summary

The plugin calls EdmxI18nProvider.getTexts(Locale.ENGLISH) to resolve English i18n texts. This reads the "en" key from the compiled i18n.json, which is only populated when i18n_en.properties exists. Having only i18n.properties (the CAP convention default fallback) was not sufficient.

Fix: When getTexts(Locale.ENGLISH) returns no app-specific keys, fall back to getTexts(Locale.ROOT) which reads from the default i18n.properties file. putIfAbsent ensures that explicit i18n_en.properties entries always take precedence when both files exist.

Changes

• I18nHelper: when resolving English i18n texts, merge in Locale.ROOT entries as fallback via putIfAbsent

[Schmarvinius]

lgtm but i think you should add a short sentence about it in the changelog

[Schmarvinius]

Not really a fix but more of a change or addition, but it's ok

[busehalis-sap]

Actually, technically it is a fix. Without i18n_en.properties, the application was throwing an exception at startup, something like:

Missing or unresolved @notification.template.title for event 'BookOrdered', locale 'en'. Ensure the annotation is present and the i18n key exists in your properties file.

This shouldn't happen for English since i18n.properties (no suffix) is the CAP convention for the default/English fallback. The fix makes the plugin treat it as such.