1. Authentication Library (src/lib/auth.ts)

2. Authentication Routes
3. Updated Data Store (`src/lib/db.ts`)
4. Updated API Routes
5. Updated Frontend Component (`src/components/BikeBuilderApp.tsx`)

prisma/schema.prisma

@@ -8,6 +8,18 @@ datasource db {
   url      = env("DATABASE_URL")
 }
 
+model User {
+  id           String            @id @default(cuid())
+  email        String            @unique
+  passwordHash String
+  name         String?
+  createdAt    DateTime          @default(now())
+  updatedAt    DateTime          @updatedAt
+  builds       BikeBuild[]
+  reviews      RideReview[]
+  preference   RiderPreference?
+}
+
 model Product {
   id        String   @id
   category  String
@@ -36,6 +48,8 @@ model BikeBuild {
   rearTireId    String?
   setup         String
   imagePath     String?
+  userId        String
+  user          User         @relation(fields: [userId], references: [id], onDelete: Cascade)
   reviews       RideReview[]
   createdAt     DateTime     @default(now())
   updatedAt     DateTime     @updatedAt
@@ -45,6 +59,8 @@ model RideReview {
   id         String    @id @default(cuid())
   buildId    String
   build      BikeBuild @relation(fields: [buildId], references: [id], onDelete: Cascade)
+  userId     String
+  user       User      @relation(fields: [userId], references: [id], onDelete: Cascade)
   suspFeel   Int
   frontGrip  Int
   rearGrip   Int
@@ -60,7 +76,9 @@ model RideReview {
 }
 
 model RiderPreference {
-  id             String   @id @default("default")
+  id             String   @id @default(cuid())
+  userId         String   @unique
+  user           User     @relation(fields: [userId], references: [id], onDelete: Cascade)
   harshTendency  Int      @default(0)
   softTendency   Int      @default(0)
   gripPreference Int      @default(0)