Initial commit: Next Step health management app

A calm, reliable app to help manage appointments, medications, and notes
for chemo patients and their families.

Features:
- Today dashboard with next appointment and medications due
- Medication tracking with multiple schedule types (fixed times, interval, weekdays, PRN)
- One-tap dose logging with 5-minute undo window
- Questions for doctor tracking
- Family sharing with workspace model and invite links
- Offline-first with IndexedDB and sync
- Docker Compose deployment with Tailscale Funnel support

Tech stack:
- Next.js 14 (App Router) + TypeScript + Tailwind CSS
- PostgreSQL + Prisma
- Argon2 password hashing + session cookies
- Dexie.js for IndexedDB

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

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

@@ -0,0 +1,71 @@
+import { NextRequest, NextResponse } from 'next/server'
+import { prisma } from '@/lib/db/prisma'
+import { hashPassword, createSession, getSessionCookieConfig } from '@/lib/auth'
+import { registerSchema } from '@/lib/validation'
+import { withRateLimit } from '@/lib/auth/middleware'
+
+async function handler(req: NextRequest) {
+  try {
+    const body = await req.json()
+    const result = registerSchema.safeParse(body)
+
+    if (!result.success) {
+      return NextResponse.json(
+        { error: 'Invalid input', details: result.error.flatten() },
+        { status: 400 }
+      )
+    }
+
+    const { email, password, name } = result.data
+
+    // Check if user exists
+    const existing = await prisma.user.findUnique({
+      where: { email: email.toLowerCase() },
+    })
+
+    if (existing) {
+      return NextResponse.json(
+        { error: 'An account with this email already exists' },
+        { status: 409 }
+      )
+    }
+
+    // Create user
+    const passwordHash = await hashPassword(password)
+    const user = await prisma.user.create({
+      data: {
+        email: email.toLowerCase(),
+        passwordHash,
+        name,
+      },
+      select: {
+        id: true,
+        email: true,
+        name: true,
+      },
+    })
+
+    // Create session
+    const userAgent = req.headers.get('user-agent') || undefined
+    const ipAddress = req.headers.get('x-forwarded-for')?.split(',')[0]
+    const token = await createSession(user.id, userAgent, ipAddress)
+    const cookieConfig = getSessionCookieConfig(token)
+
+    const response = NextResponse.json({
+      user,
+      message: 'Account created successfully',
+    })
+
+    response.cookies.set(cookieConfig)
+
+    return response
+  } catch (error) {
+    console.error('Registration error:', error)
+    return NextResponse.json(
+      { error: 'Registration failed' },
+      { status: 500 }
+    )
+  }
+}
+
+export const POST = withRateLimit(handler)