security: fix unauthenticated file upload/RCE risk, TLS bypass, XSS, and broken gift-card/review columns

- admin/api/upload-splash.php had NO admin-auth check (included the public
  customer header, not admin/includes/header.php) and both upload endpoints
  trusted the client-supplied MIME type and filename extension, so an
  attacker could name a file "shell.php", spoof Content-Type: image/png,
  and get PHP written into a web-reachable uploads/ directory. Added
  AdminAuth check and centralized real-content validation (getimagesize +
  server-side extension mapping) in a new handleImageUpload() helper used
  by both admin/upload-image.php and admin/api/upload-splash.php.
- Removed CURLOPT_SSL_VERIFYPEER => false from the CyberMail email calls
  in includes/email.php and includes/functions.php (MITM risk on the API
  key). Rewrote functions.php's sendEmail() as a thin wrapper around
  Email::send() so there's one implementation instead of two that could
  drift (this is what had the second copy of the TLS bypass).
- Escaped customer-controlled fields (customer_name, tracking info, reset
  URL) before interpolating into outbound HTML emails — name is free text
  from registration/checkout with no length/char restriction, so it was
  stored-HTML-injectable into every transactional email.
- Fixed api/redeem-gift-card.php referencing a nonexistent `balance` column
  on gift_cards (actual column is current_balance) — gift card redemption
  was completely broken, always returning "no remaining balance".
- Fixed api/submit-review.php inserting into nonexistent `content`/`status`
  columns on reviews (actual columns are `comment`/`is_approved`) — review
  submission was crashing on every request.
- Hardened .htaccess: block /db/*, /.git/*, and *.sql. Live site currently
  serves db/schema.sql and the full .git directory (including .git/config,
  which contains a GitHub PAT with push access) over HTTP — the existing
  config/includes RedirectMatch rules are also not being enforced live,
  see report for details; this needs a server-level fix too.
- Cleaned up README's leftover install instructions pointing at a deleted
  create-admin.php with a documented default password.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

includes/functions.php

@@ -349,31 +349,15 @@ function getCartTotal() {
 }
 
 /**
- * Send email via CyberMail API
+ * Send email via CyberMail API.
+ * Thin wrapper around Email::send() (includes/email.php) so there is a
+ * single implementation of the CyberMail HTTP call, TLS settings, and
+ * error handling instead of two copies that can drift out of sync.
  */
 function sendEmail($to, $subject, $htmlContent, $textContent = '') {
-    $apiKey = getSetting('cybermail_api_key', defined('CYBERMAIL_API_KEY') ? CYBERMAIL_API_KEY : '');
-    $from     = getSetting('cybermail_from_email', 'noreply@tomsjavajive.com');
-    $fromName = getSetting('cybermail_from_name',  "Tom's Java Jive");
-    if (!$apiKey) {
-        error_log('[TJJ sendEmail] CYBERMAIL_API_KEY not configured');
-        return false;
-    }
-    $payload = ['from' => $from, 'from_name' => $fromName, 'to' => $to, 'subject' => $subject, 'html' => $htmlContent];
-    if ($textContent) $payload['text'] = $textContent;
-    $ch = curl_init('https://platform.cyberpersons.com/email/v1/send');
-    curl_setopt_array($ch, [
-        CURLOPT_RETURNTRANSFER => true, CURLOPT_POST => true,
-        CURLOPT_POSTFIELDS     => json_encode($payload),
-        CURLOPT_HTTPHEADER     => ['Authorization: Bearer ' . $apiKey, 'Content-Type: application/json'],
-        CURLOPT_TIMEOUT        => 20, CURLOPT_SSL_VERIFYPEER => false,
-    ]);
-    $response = curl_exec($ch);
-    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
-    curl_close($ch);
-    if ($httpCode === 202) return true;
-    error_log('[TJJ sendEmail] CyberMail HTTP ' . $httpCode . ' — ' . $response);
-    return false;
+    require_once __DIR__ . '/email.php';
+    $result = emailService()->send($to, $subject, $htmlContent, $textContent ?: null);
+    return $result['success'] ?? false;
 }
 
 /**
@@ -382,3 +366,57 @@ function sendEmail($to, $subject, $htmlContent, $textContent = '') {
 function logActivity($action, $details = [], $userId = null) {
     // Implement activity logging if needed
 }
+
+/**
+ * Validate and save an uploaded image, verifying the ACTUAL file content
+ * (not the client-supplied MIME type or filename extension, both of which
+ * are attacker-controlled) before writing it to disk. Used by every admin
+ * image-upload endpoint so the checks live in exactly one place.
+ *
+ * @param string $fieldName  Key in $_FILES to read
+ * @param string $destDir    Absolute directory to save into (created if missing)
+ * @param string $prefix     Filename prefix, e.g. "product_" or "splash_"
+ * @return array ['success' => bool, 'url' => string, 'path' => string] or ['error' => string]
+ */
+function handleImageUpload(string $fieldName, string $destDir, string $prefix = 'img_'): array {
+    if (empty($_FILES[$fieldName]) || $_FILES[$fieldName]['error'] !== UPLOAD_ERR_OK) {
+        return ['error' => 'No file received'];
+    }
+
+    $file = $_FILES[$fieldName];
+
+    if ($file['size'] > MAX_UPLOAD_SIZE) {
+        return ['error' => 'File too large. Maximum ' . (MAX_UPLOAD_SIZE / (1024 * 1024)) . 'MB.'];
+    }
+
+    // Never trust $file['type'] (client-supplied) or the extension in
+    // $file['name'] (attacker-supplied) — inspect the real file bytes.
+    $imageInfo = @getimagesize($file['tmp_name']);
+    if ($imageInfo === false) {
+        return ['error' => 'File is not a valid image.'];
+    }
+
+    $extensionByMime = [
+        'image/jpeg' => 'jpg',
+        'image/png'  => 'png',
+        'image/gif'  => 'gif',
+        'image/webp' => 'webp',
+    ];
+    $mime = $imageInfo['mime'];
+    if (!in_array($mime, ALLOWED_IMAGE_TYPES, true) || !isset($extensionByMime[$mime])) {
+        return ['error' => 'Invalid file type. Use JPG, PNG, WebP, or GIF.'];
+    }
+
+    if (!is_dir($destDir)) {
+        mkdir($destDir, 0755, true);
+    }
+
+    $filename = $prefix . time() . '_' . bin2hex(random_bytes(4)) . '.' . $extensionByMime[$mime];
+    $filepath = rtrim($destDir, '/\\') . '/' . $filename;
+
+    if (!move_uploaded_file($file['tmp_name'], $filepath)) {
+        return ['error' => 'Failed to save file. Check directory permissions.'];
+    }
+
+    return ['success' => true, 'filename' => $filename, 'path' => $filepath];
+}