add option to create location in all subsequent months

- Added toggle in LocationEditForm for adding locations to future months (disabled by default)
- Modified updateOrAddLocation action to support batch creation across subsequent months
- Only creates locations in months where no location with same name exists
- Added translations for toggle text in Croatian and English
- Fixed unused variable warning in deleteLocationById
- Improved auth.ts development comments for clarity

🤖 Generated with [Claude Code](https://claude.ai/code)

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

messages/en.json

@@ -98,6 +98,7 @@
     "save-button": "Save",
     "cancel-button": "Cancel",
     "delete-tooltip": "Delete realestate",
+    "add-to-subsequent-months": "Add to all subsequent months",
     "validation": {
       "location-name-required": "Relaestate name is required"
     }