Add initial Neptune Frontend setup

Initial setup of the Neptune frontend project, including Dockerfile, environment files, TypeScript configuration, and essential components. Added basic page structures for dashboard and wallet, and configured Tailwind CSS and postcss.

Dockerfile

@@ -0,0 +1,31 @@
+# Étape 1 : Build
+FROM node:18-alpine AS builder
+
+WORKDIR /app
+RUN npm install -g pnpm
+# Copier package.json et installer les dépendances
+COPY pnpm-lock.yaml ./
+COPY package.json ./
+RUN pnpm install
+
+# Copier le reste du code et construire l'application
+COPY . .
+RUN pnpm run build
+
+# Étape 2 : Serveur de production
+FROM node:18-alpine
+
+WORKDIR /app
+
+# Copier uniquement les fichiers nécessaires
+COPY --from=builder /app/package.json ./
+COPY --from=builder /app/pnpm-lock.yaml ./
+COPY --from=builder /app/.next ./.next
+COPY --from=builder /app/public ./public
+COPY --from=builder /app/node_modules ./node_modules
+
+# Exposer le port de l'application
+EXPOSE 3000
+
+# Commande de démarrage
+CMD ["npm", "start"]