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.

.env.example

@@ -0,0 +1,22 @@
+# ============================================================
+# SlaapKampioen — omgevingsvariabelen
+# Kopieer dit bestand naar .env en vul de waarden in.
+# Commit NOOIT je .env naar git!
+# ============================================================
+
+# --- Database ---
+# Automatisch gebruikt door docker-compose
+POSTGRES_PASSWORD=verander_dit_wachtwoord
+
+# --- NextAuth ---
+# Jouw publieke URL (incl. protocol, geen trailing slash)
+NEXTAUTH_URL=https://slaap.jouwdomein.be
+
+# Willekeurig geheim — genereer met: openssl rand -base64 32
+NEXTAUTH_SECRET=
+
+# --- Discord OAuth ---
+# Maak een app aan op https://discord.com/developers/applications
+# Redirect URI instellen op: https://slaap.jouwdomein.be/api/auth/callback/discord
+DISCORD_CLIENT_ID=
+DISCORD_CLIENT_SECRET=