Added authentication functionality and simple role based model

register.php

@@ -0,0 +1,42 @@
+<?php
+require 'db.php';
+require 'auth.php';
+
+header('Content-Type: application/json');
+
+$data = json_decode(file_get_contents('php://input'), true);
+$email = strtolower(trim($data['email'] ?? ''));
+$password = strval($data['password'] ?? '');
+
+if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
+    http_response_code(400);
+    echo json_encode(['success' => false, 'error' => 'Invalid email']);
+    exit;
+}
+if (strlen($password) < 8) {
+    http_response_code(400);
+    echo json_encode(['success' => false, 'error' => 'Password must be at least 8 characters']);
+    exit;
+}
+
+$hash = password_hash($password, PASSWORD_DEFAULT);
+
+// Standard role id from roles table
+$stmt = $pdo->prepare("SELECT id FROM roles WHERE name = 'standard' LIMIT 1");
+$stmt->execute();
+$role_id = intval($stmt->fetchColumn());
+
+if ($role_id <= 0) {
+    http_response_code(500);
+    echo json_encode(['success' => false, 'error' => "Role 'standard' not found"]);
+    exit;
+}
+
+try {
+    $stmt = $pdo->prepare("INSERT INTO users (email, password_hash, role_id) VALUES (?, ?, ?)");
+    $stmt->execute([$email, $hash, $role_id]);
+    echo json_encode(['success' => true]);
+} catch (Throwable $e) {
+    http_response_code(409);
+    echo json_encode(['success' => false, 'error' => 'Account already exists']);
+}