feat: add sleep tracking features with leaderboard and user authentication

- Implemented a new HomePage component displaying the leaderboard.
- Created Providers component for session management using next-auth.
- Developed Header component for navigation and user authentication.
- Added Leaderboard component to fetch and display sleep data.
- Introduced SleepCard component for individual sleep entries.
- Created SleepForm component for logging sleep data with manual input options.
- Added SleepPhaseBar component to visualize sleep phases.
- Implemented utility functions for formatting and calculating sleep data.
- Set up authentication with Discord using next-auth and Prisma.
- Configured middleware for protected routes.
- Added TypeScript definitions for next-auth session.
- Configured Tailwind CSS for styling.
- Initialized TypeScript configuration for the project.

prisma/schema.prisma

@@ -0,0 +1,89 @@
+generator client {
+  provider = "prisma-client-js"
+}
+
+datasource db {
+  provider = "postgresql"
+  url      = env("DATABASE_URL")
+}
+
+// --- NextAuth required models ---
+
+model Account {
+  id                String  @id @default(cuid())
+  userId            String
+  type              String
+  provider          String
+  providerAccountId String
+  refresh_token     String? @db.Text
+  access_token      String? @db.Text
+  expires_at        Int?
+  token_type        String?
+  scope             String?
+  id_token          String? @db.Text
+  session_state     String?
+
+  user User @relation(fields: [userId], references: [id], onDelete: Cascade)
+
+  @@unique([provider, providerAccountId])
+}
+
+model Session {
+  id           String   @id @default(cuid())
+  sessionToken String   @unique
+  userId       String
+  expires      DateTime
+  user         User     @relation(fields: [userId], references: [id], onDelete: Cascade)
+}
+
+model VerificationToken {
+  identifier String
+  token      String   @unique
+  expires    DateTime
+
+  @@unique([identifier, token])
+}
+
+// --- App models ---
+
+model User {
+  id            String       @id @default(cuid())
+  name          String?
+  email         String?      @unique
+  emailVerified DateTime?
+  image         String?
+  accounts      Account[]
+  sessions      Session[]
+  sleepEntries  SleepEntry[]
+  createdAt     DateTime     @default(now())
+}
+
+model SleepEntry {
+  id           String    @id @default(cuid())
+  userId       String
+  user         User      @relation(fields: [userId], references: [id], onDelete: Cascade)
+
+  // The date of the night (e.g. 2024-01-15 = night of 14→15 jan)
+  date         DateTime  @db.Date
+
+  // Optional: exact times
+  bedtime      DateTime?
+  wakeTime     DateTime?
+
+  // Required: total sleep
+  totalMinutes Int
+
+  // Optional: phase breakdown (in minutes)
+  deepMinutes  Int?
+  lightMinutes Int?
+  remMinutes   Int?
+  awakeMinutes Int?
+  awakeCount   Int?
+
+  notes        String?
+
+  createdAt    DateTime  @default(now())
+  updatedAt    DateTime  @updatedAt
+
+  @@unique([userId, date])
+}