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/globals.css

@@ -0,0 +1,37 @@
+@tailwind base;
+@tailwind components;
+@tailwind utilities;
+
+@layer base {
+  :root {
+    --background: 0 0% 100%;
+    --foreground: 222.2 84% 4.9%;
+    --card: 0 0% 100%;
+    --card-foreground: 222.2 84% 4.9%;
+    --popover: 0 0% 100%;
+    --popover-foreground: 222.2 84% 4.9%;
+    --primary: 221.2 83.2% 53.3%;
+    --primary-foreground: 210 40% 98%;
+    --secondary: 210 40% 96.1%;
+    --secondary-foreground: 222.2 47.4% 11.2%;
+    --muted: 210 40% 96.1%;
+    --muted-foreground: 215.4 16.3% 46.9%;
+    --accent: 210 40% 96.1%;
+    --accent-foreground: 222.2 47.4% 11.2%;
+    --destructive: 0 84.2% 60.2%;
+    --destructive-foreground: 210 40% 98%;
+    --border: 214.3 31.8% 91.4%;
+    --input: 214.3 31.8% 91.4%;
+    --ring: 221.2 83.2% 53.3%;
+    --radius: 0.5rem;
+  }
+}
+
+@layer base {
+  * {
+    @apply border-border;
+  }
+  body {
+    @apply bg-background text-foreground;
+  }
+}