feat: initial NFC Attendance Hub implementation

- Multi-tenant client management with unique API keys
- Semaphore SMS integration (per-client key + sender name + credit balance)
- DB-based SMS queue with 3-attempt retry and exponential backoff
- Failed SMS dashboard with manual retry button
- Reports page with date/client filter and CSV export
- Admin auth via NextAuth (email/password)
- Docker Compose setup (app + PostgreSQL 16)
- Prisma 5 schema with SmsQueue, SmsLog, Client, User models

Tech: Next.js 14 App Router + TypeScript + Tailwind CSS + Prisma + PostgreSQL

app/api/sms/failed/route.ts

@@ -0,0 +1,24 @@
+import { NextRequest, NextResponse } from 'next/server'
+import { getServerSession } from 'next-auth'
+import { authOptions } from '@/lib/auth'
+import { prisma } from '@/lib/prisma'
+
+export async function GET(req: NextRequest) {
+  const session = await getServerSession(authOptions)
+  if (!session) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+
+  const { searchParams } = new URL(req.url)
+  const clientId = searchParams.get('clientId')
+
+  const failed = await prisma.smsQueue.findMany({
+    where: {
+      status: 'FAILED',
+      ...(clientId ? { clientId } : {}),
+    },
+    include: { client: { select: { name: true } } },
+    orderBy: { updatedAt: 'desc' },
+    take: 200,
+  })
+
+  return NextResponse.json(failed)
+}