Implement bill forwarding strategy with radio button persistence

Added billFwdStrategy field to store user's choice for when to forward
utility bills to tenants, with database persistence and UI updates.

Changes:
- Added billFwdStrategy field to BillingLocation interface ("when-payed" | "when-attached")
- Updated FormSchema to validate billFwdStrategy enum values
- Modified updateOrAddLocation to persist billFwdStrategy in all database operations
- Defaults to "when-payed" (first option) when no value exists in database
- Updated LocationEditForm radio buttons to use persisted database values
- Radio button selection is preserved across edits and restored from database
- Renamed autoTenantNotification to autoBillFwd throughout codebase
- Updated localization strings for bill forwarding features

Form behavior:
- New locations: "when-payed" radio selected by default
- Existing locations: Radio selection matches stored database value
- Value persisted in current, subsequent, and all month update operations

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

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

messages/en.json

@@ -124,14 +124,19 @@
   "location-edit-form": {
     "location-name-placeholder": "Realestate name",
     "notes-placeholder": "Notes",
-    "generate-tenant-code": "generate 2D code for tenant",
+    "tenant-2d-code-legend": "TENANT 2D CODE",
+    "tenant-2d-code-toggle-label": "generate 2d code",
     "tenant-first-name-label": "Tenant First Name",
     "tenant-first-name-placeholder": "Enter tenant's first name",
     "tenant-last-name-label": "Tenant Last Name",
     "tenant-last-name-placeholder": "Enter tenant's last name",
-    "auto-utility-bill-forwarding": "automatic utility bill forwarding",
+    "auto-utility-bill-forwarding-legend": "AUTOMATIC UTILITY BILL FORWARDING",
+    "auto-utility-bill-forwarding-toggle-label": "forward utility bills",
     "tenant-email-label": "Tenant Email",
     "tenant-email-placeholder": "Enter tenant's email",
+    "utility-bill-forwarding-strategy-label": "Forward utility bills when ...",
+    "utility-bill-forwarding-when-payed": "all bills are marked as paid",
+    "utility-bill-forwarding-when-attached": "a bill (PDF) is attached to all items",
     "warning-missing-tenant-names": "Warning: Tenant first and last name are missing. The 2D barcode will not be displayed to the tenant when they open the shared link until both fields are filled in.",
     "save-button": "Save",
     "cancel-button": "Cancel",