refactor: rename share URL path from location to bills-due

- Renamed directory: app/[locale]/share/location -> app/[locale]/share/bills-due
- Updated all URL references in web-app (billActions, locationActions, ViewBillCard)
- Updated all URL references in email-worker templates (4 email templates)
- Updated documentation in sprints/email-worker.md

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

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

web-app/app/[locale]/share/bills-due/[id]/page.tsx

@@ -0,0 +1,14 @@
+import { Suspense } from 'react';
+import LocationViewPage from './LocationViewPage';
+import { Main } from '@/app/ui/Main';
+import { LocationEditFormSkeleton } from '@/app/ui/LocationEditForm';
+
+export default async function Page({ params: { id } }: { params: { id: string } }) {
+    return (
+        <Main>
+            <Suspense fallback={<LocationEditFormSkeleton />}>
+                <LocationViewPage shareId={id} />
+            </Suspense>
+        </Main>
+    );
+}