init: projet complet copymail pour Raspberry Pi

Stack: Nginx + PHP 8.2 + MariaDB + Postfix + Dovecot + Samba
- install.sh: script installation automatisé pour RPi OS Bookworm
- Interface web: visionneuse mails + admin (comptes, domaine, dashboard)
- Chaque compte mail génère automatiquement un share Samba
- Processeur cron: extraction pièces jointes via zbateson/mail-mime-parser
- Zéro injection SQL (PDO + prepared statements)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/includes/auth.php

@@ -0,0 +1,39 @@
+<?php
+
+function auth_start(): void {
+    if (session_status() === PHP_SESSION_NONE) {
+        session_name('copymail_sess');
+        session_start();
+    }
+}
+
+function auth_check(): void {
+    auth_start();
+    if (empty($_SESSION['admin_id'])) {
+        header('Location: /login.php');
+        exit;
+    }
+}
+
+function auth_login(string $username, string $password): bool {
+    $st = db()->prepare('SELECT id, password FROM admin_users WHERE username = ? LIMIT 1');
+    $st->execute([$username]);
+    $row = $st->fetch();
+    if ($row && password_verify($password, $row['password'])) {
+        $_SESSION['admin_id']   = $row['id'];
+        $_SESSION['admin_user'] = $username;
+        return true;
+    }
+    return false;
+}
+
+function auth_logout(): void {
+    auth_start();
+    session_destroy();
+    header('Location: /login.php');
+    exit;
+}
+
+function current_user(): string {
+    return $_SESSION['admin_user'] ?? '';
+}