feat: subscription tiers, period filter, dashboards, docs

- Add subscription tiers (Basic/Pro/Business) with listing limits and dynamic commission
- Add daily/monthly period filter on rentals page
- Add landlord dashboard with earnings chart, stat cards, property performance
- Add landlord subscription management page
- Add tenant dashboard with upcoming stays
- Add business model documentation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/routes/booking.ts

@@ -6,6 +6,7 @@ import { createBookingSchema, rejectBookingSchema, cancelBookingSchema } from '.
 import { AppError } from '../middleware/errorHandler.js';
 import { checkAvailability, calculateCancellationRefund, autoTransitionBooking } from '../utils/rental.js';
 import { getPlatformConfig } from '../utils/moderation.js';
+import { getLandlordTier, TIER_CONFIG } from '../utils/subscription.js';
 
 const router = Router();
 
@@ -111,8 +112,9 @@ router.post('/', authenticate, validate(createBookingSchema), async (req, res, n
     }
 
     const config = await getPlatformConfig();
+    const landlordTier = await getLandlordTier(rental.landlordId);
     const subtotal = pricePerPeriod * totalPeriods;
-    const commissionRate = config.rentalCommissionPercent;
+    const commissionRate = TIER_CONFIG[landlordTier].commissionPercent;
     const commissionAmount = subtotal * (commissionRate / 100);
     const depositAmount = rental.depositAmount || 0;
     const totalAmount = subtotal + depositAmount;