REFACTOR(repo): simplify project structure

- Move services/nextjs to nextjs/
- Move deploy/docker/Dockerfile.prod to Dockerfile
- Add GitHub Actions workflows (ci.yml, build.yml)
- Remove deploy/, services/, scripts/ folders

nextjs/app/api/auth/register/route.ts

@@ -0,0 +1,76 @@
+import { NextRequest, NextResponse } from 'next/server'
+import { createUser, generateToken } from '@/shared/lib/auth'
+import { db } from '@/shared/lib/db'
+
+export async function POST(req: NextRequest) {
+  try {
+    const { email, password, name } = await req.json()
+
+    // Validation
+    if (!email || !password) {
+      return NextResponse.json(
+        { error: 'Email and password are required' },
+        { status: 400 }
+      )
+    }
+
+    if (password.length < 6) {
+      return NextResponse.json(
+        { error: 'Password must be at least 6 characters' },
+        { status: 400 }
+      )
+    }
+
+    // Check if user already exists
+    const existingUser = await db.user.findUnique({
+      where: { email },
+    })
+
+    if (existingUser) {
+      return NextResponse.json(
+        { error: 'User already exists' },
+        { status: 400 }
+      )
+    }
+
+    // Create user
+    const user = await createUser(email, password, name)
+
+    // Generate JWT token
+    const token = generateToken({
+      userId: user.id,
+      email: user.email,
+    })
+
+    // Create response with user data
+    const response = NextResponse.json(
+      { 
+        message: 'User created successfully',
+        token,
+        user: {
+          id: user.id,
+          email: user.email,
+          name: user.name,
+        }
+      },
+      { status: 201 }
+    )
+
+    // Set auth token in cookie (HttpOnly for security)
+    response.cookies.set('auth-token', token, {
+      httpOnly: true,
+      secure: process.env.NODE_ENV === 'production',
+      sameSite: 'lax',
+      maxAge: 60 * 60 * 24 * 7, // 7 days
+      path: '/',
+    })
+
+    return response
+  } catch (error) {
+    console.error('Registration error:', error)
+    return NextResponse.json(
+      { error: 'Internal server error' },
+      { status: 500 }
+    )
+  }
+}