M3 Passwort-Reset und E-Mail-Verifikation ergänzen

- Auth-Token-Tabelle mit gehashten Single-Use-Tokens einführen
- Passwort-Reset und E-Mail-Verifikation als Dev-Flow bauen
- Token-Flow-Test, Smoke-Abdeckung und M3-Dokumentation aktualisieren

konto.php

@@ -3,6 +3,11 @@
 require_once __DIR__ . '/functions.php';
 
 $user = saas_require_login();
+$devVerificationToken = null;
+if (saas_should_show_auth_links() && !empty($_SESSION['saas_dev_email_verification_token'])) {
+    $devVerificationToken = (string)$_SESSION['saas_dev_email_verification_token'];
+    unset($_SESSION['saas_dev_email_verification_token']);
+}
 
 include 'header.php';
 include 'headerline.php';
@@ -17,6 +22,13 @@ include 'nav.php';
             <div class="hint-box success"><p>Das Kundenkonto wurde angelegt.</p></div>
         <?php endif; ?>
 
+        <?php if ($devVerificationToken !== null): ?>
+            <div class="hint-box success">
+                <p>Der Verifizierungslink wurde vorbereitet.</p>
+                <p><a href="email-verifizieren.php?token=<?php echo saas_html($devVerificationToken); ?>">Dev-Link zur E-Mail-Verifizierung</a></p>
+            </div>
+        <?php endif; ?>
+
         <table>
             <tr>
                 <th>Name</th>
@@ -38,8 +50,19 @@ include 'nav.php';
                 <th>Rolle</th>
                 <td><?php echo saas_html($user['role']); ?></td>
             </tr>
+            <tr>
+                <th>E-Mail bestaetigt</th>
+                <td><?php echo $user['email_verified_at'] !== null ? 'ja' : 'nein'; ?></td>
+            </tr>
         </table>
 
+        <?php if ($user['email_verified_at'] === null): ?>
+            <form method="post" action="email-verifikation-senden.php">
+                <?php echo app_csrf_field(); ?>
+                <button type="submit">E-Mail-Verifizierung vorbereiten</button>
+            </form>
+        <?php endif; ?>
+
         <?php if (saas_can_manage_tenant_settings($user)): ?>
             <ul class="actions">
                 <li><a href="mandant-einstellungen.php" class="button">Mandant-Einstellungen</a></li>