feat: add rent-due share page for rent payment information

Created a new /share/rent-due/ page to display rent payment information
separately from utility bills.

Changes:
- Created /share/rent-due/[id]/ page structure with RentViewPage component
- Created ViewRentCard component to display rent amount and payment info
- Added uploadRentProofOfPayment action for tenant proof upload
- Added translation keys for rent-specific labels (en/hr)
- Updated rent email templates to link to /share/rent-due/ instead of /share/bills-due/
- Updated documentation to reflect new URL structure

The rent page displays:
- Rent amount
- IBAN or Revolut payment information with QR/barcode
- Rent proof of payment upload (when enabled)

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

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

web-app/messages/en.json

@@ -79,7 +79,10 @@
       "payment-description-label": "Payment description:",
       "upload-proof-of-payment-legend": "Proof of payment",
       "upload-proof-of-payment-label": "Here you can upload proof of payment:",
-      "revolut-link-text": "Pay with Revolut"
+      "revolut-link-text": "Pay with Revolut",
+      "rent-amount-label": "Rent amount:",
+      "upload-rent-proof-of-payment-legend": "Rent proof of payment",
+      "upload-rent-proof-of-payment-label": "Here you can upload rent proof of payment:"
     },
     "month-card": {
       "total-due-label": "Monthly due total:",