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/v1/sms/send/route.ts

@@ -0,0 +1,58 @@
+import { NextRequest, NextResponse } from 'next/server'
+import { prisma } from '@/lib/prisma'
+
+export async function POST(req: NextRequest) {
+  try {
+    const apiKey = req.headers.get('x-api-key')
+    if (!apiKey) {
+      return NextResponse.json({ error: 'Missing X-API-Key header' }, { status: 401 })
+    }
+
+    const client = await prisma.client.findUnique({ where: { apiKey } })
+    if (!client || !client.isActive) {
+      return NextResponse.json({ error: 'Invalid or inactive API key' }, { status: 403 })
+    }
+
+    const body = await req.json()
+    const { student_name, student_id, parent_phone, event, timestamp, message } = body
+
+    if (!student_name || !student_id || !parent_phone || !event || !timestamp) {
+      return NextResponse.json(
+        { error: 'Missing required fields: student_name, student_id, parent_phone, event, timestamp' },
+        { status: 400 }
+      )
+    }
+
+    if (!['time_in', 'time_out'].includes(event)) {
+      return NextResponse.json({ error: 'event must be "time_in" or "time_out"' }, { status: 400 })
+    }
+
+    const queueEntry = await prisma.smsQueue.create({
+      data: {
+        clientId: client.id,
+        studentName: student_name,
+        studentId: student_id,
+        parentPhone: parent_phone,
+        event,
+        timestamp: new Date(timestamp),
+        message: message || null,
+        status: 'PENDING',
+      },
+    })
+
+    // Trigger queue processing in background (fire and forget)
+    fetch(`${process.env.NEXTAUTH_URL}/api/queue/process`, {
+      method: 'POST',
+      headers: { 'x-internal-key': process.env.INTERNAL_API_KEY || '' },
+    }).catch(() => {})
+
+    return NextResponse.json({
+      success: true,
+      queueId: queueEntry.id,
+      message: 'SMS queued for delivery',
+    }, { status: 202 })
+  } catch (err: any) {
+    console.error('[SMS Send]', err)
+    return NextResponse.json({ error: 'Internal server error' }, { status: 500 })
+  }
+}