Add auto tenant notification toggle to LocationEditForm

Added toggle to control automatic tenant notifications with conditional
email field visibility based on the toggle state.

Changes:
- Added autoTenantNotification field to BillingLocation interface
- Updated LocationEditForm with "Notify tenant automatically" toggle
- Email field now only visible when autoTenantNotification is enabled
- Toggle appears after tenant name fields (when generateTenantCode is active)
- Updated updateOrAddLocation action to persist autoTenantNotification flag
- Added localization strings for toggle (Croatian/English)

Field visibility hierarchy:
1. Generate 2D code toggle (always visible)
2. Tenant name fields (visible when #1 is ON)
3. Auto notification toggle (visible when #1 is ON)
4. Email field (visible when #1 AND #3 are ON)

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

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

app/lib/db-types.ts

@@ -49,6 +49,8 @@ export interface BillingLocation {
     tenantFirstName?: string | null;
     /** (optional) tenant last name */
     tenantLastName?: string | null;
+    /** (optional) whether to automatically notify tenant */
+    autoTenantNotification?: boolean | null;
     /** (optional) tenant email */
     tenantEmail?: string | null;
 };