chore: release v1.5.0 (#67)

* chore: release v1.4.0

* feat: timezone-aware locale formatting

- Add TIMEZONE_TO_REGION map for 50+ timezones worldwide
- Combine app language with timezone region (e.g., en + Europe/Berlin → en-DE)
- Fix times displaying in wrong timezone (treated as UTC instead of local)
- Add parseLocalDateTime() to handle ISO strings without UTC conversion
- Users now get regional formatting (24h time, local date format) regardless of app language
- Swedish user with en-SE locale now gets yyyy-mm-dd format and 24h time
- German user with en-DE locale gets dd.mm.yyyy format and 24h time
- Add missing i18n translation key 'lastSent'
- Update all getSystemLocale() calls to pass app language parameter

* chore: release v1.5.0

* fix: timezone-independent test for CI (use 14:00 instead of 22:00)

* fix: make timezone test independent of server timezone

frontend/src/i18n/de.json

@@ -52,6 +52,7 @@
       "allStockOk": "Bestand OK",
       "allOk": "✓ Alles OK",
       "lastReminder": "Letzte Erinnerung",
+      "lastSent": "Zuletzt gesendet",
       "next": "Nächste",
       "nextIn": "Nächste",
       "inDays": "in {{days}} Tagen",

frontend/src/i18n/en.json

@@ -54,6 +54,7 @@
       "allStockOk": "All stock OK",
       "allOk": "✓ All OK",
       "lastReminder": "Last reminder",
+      "lastSent": "Last sent",
       "next": "Next",
       "nextIn": "Next",
       "inDays": "in {{days}} days",