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

prisma/schema.prisma

@@ -0,0 +1,90 @@
+generator client {
+  provider = "prisma-client-js"
+}
+
+datasource db {
+  provider = "postgresql"
+  url      = env("DATABASE_URL")
+}
+
+model User {
+  id        String   @id @default(cuid())
+  email     String   @unique
+  password  String
+  name      String?
+  role      Role     @default(ADMIN)
+  createdAt DateTime @default(now())
+  updatedAt DateTime @updatedAt
+}
+
+model Client {
+  id           String       @id @default(cuid())
+  name         String
+  slug         String       @unique
+  apiKey       String       @unique @default(cuid())
+  isActive     Boolean      @default(true)
+  semaphoreKey String?
+  senderName   String?      @default("NFC-HUB")
+  createdAt    DateTime     @default(now())
+  updatedAt    DateTime     @updatedAt
+  smsLogs      SmsLog[]
+  smsQueue     SmsQueue[]
+}
+
+model SmsQueue {
+  id           String     @id @default(cuid())
+  clientId     String
+  client       Client     @relation(fields: [clientId], references: [id])
+  studentName  String
+  studentId    String
+  parentPhone  String
+  event        EventType
+  timestamp    DateTime
+  message      String?
+  status       SmsStatus  @default(PENDING)
+  attempts     Int        @default(0)
+  lastError    String?
+  scheduledAt  DateTime   @default(now())
+  processedAt  DateTime?
+  createdAt    DateTime   @default(now())
+  updatedAt    DateTime   @updatedAt
+  smsLog       SmsLog?
+}
+
+model SmsLog {
+  id          String    @id @default(cuid())
+  clientId    String
+  client      Client    @relation(fields: [clientId], references: [id])
+  queueId     String    @unique
+  queue       SmsQueue  @relation(fields: [queueId], references: [id])
+  phone       String
+  message     String
+  status      LogStatus
+  semaphoreId String?
+  errorReason String?
+  sentAt      DateTime  @default(now())
+  createdAt   DateTime  @default(now())
+}
+
+enum Role {
+  ADMIN
+  VIEWER
+}
+
+enum EventType {
+  time_in
+  time_out
+}
+
+enum SmsStatus {
+  PENDING
+  PROCESSING
+  SENT
+  FAILED
+  RETRYING
+}
+
+enum LogStatus {
+  SUCCESS
+  FAILED
+}