6 catalog data and mode mappers (#25)

* supabase product proxy and rendering

* minor pipeline refactor

* refactoring and demand estimation

* trackion of date index searching

* fixing changes of imports

* data seeding

* chore: airline basic refactor

* feat: huge push of product changes and item review with cart

* refactored design

* chore: moving route elsewhere and align

* fix: build of web/

* chore: fixing paper build

* fixing chars

web/src/lib/hotel-utils.ts

@@ -0,0 +1,71 @@
+export interface HotelProduct {
+  id: string;
+  room_type: string;
+  date_index: number;
+  metadata: {
+    amenities?: string[];
+    total?: number;
+    image_url?: string;
+    base_price?: number;
+    name?: string;
+    refundable?: boolean;
+  };
+  availability: number;
+}
+
+export interface Hotel {
+  id: string;
+  name: string;
+  roomType: string;
+  checkIn: string;
+  checkOut: string;
+  dateIndex: number;
+  amenities: string[];
+  refundable: boolean;
+  pricePerNight: number;
+  nights: number;
+}
+
+const EPOCH = new Date(0);
+
+export const transformProduct = (p: HotelProduct): Hotel => {
+  const { id, room_type, date_index, metadata } = p;
+  const checkIn = new Date(EPOCH.getTime() + date_index * 86400000);
+  const nights = 1;
+  const checkOut = new Date(checkIn.getTime() + nights * 86400000);
+
+  return {
+    id,
+    name: metadata?.name || room_type,
+    roomType: room_type,
+    checkIn: checkIn.toLocaleDateString('en-US', { month: 'short', day: 'numeric' }),
+    checkOut: checkOut.toLocaleDateString('en-US', { month: 'short', day: 'numeric' }),
+    dateIndex: date_index,
+    amenities: metadata?.amenities || [],
+    refundable: metadata?.refundable || false,
+    pricePerNight: metadata?.base_price || 100,
+    nights,
+  };
+};
+
+// convert date string to days from today
+export const dateToDaysFromToday = (dateStr: string): number => {
+  const target = new Date(dateStr);
+  target.setHours(0, 0, 0, 0);
+  const today = new Date();
+  today.setHours(0, 0, 0, 0);
+  return Math.floor((target.getTime() - today.getTime()) / 86400000);
+};
+
+// convert date string to date_index (days since epoch)
+export const dateToIndex = (dateStr: string): number => {
+  const d = new Date(dateStr);
+  return Math.floor((d.getTime() - EPOCH.getTime()) / 86400000);
+};
+
+// get current date_index
+export const todayIndex = (): number => {
+  const now = new Date();
+  now.setHours(0, 0, 0, 0);
+  return Math.floor((now.getTime() - EPOCH.getTime()) / 86400000);
+};