feat(brand): adopt platform-tools Brand feed; logo path convention in emails

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

config/functions.php

@@ -122,6 +122,24 @@ function csv_export(string $type, string $filename, string $summary, array $head
     exit;
 }
 
+// ─── Logo path (platform convention + static fallback) ───────────────────────
+// Setting <key> holds a file name. Convention: uploads/public/logo/<file>; the
+// settings page still stores uploads in assets/img/logo/ (legacy), so that is
+// accepted too. Empty setting / missing file -> $fallback (site-relative, no
+// leading slash), or '' when that file is missing as well.
+function site_logo_rel(string $settingKey, string $fallback): string {
+    $file = basename((string) setting($settingKey, ''));
+    $root = dirname(__DIR__) . '/';
+    if ($file !== '') {
+        foreach (['uploads/public/logo/', 'assets/img/logo/'] as $dir) {
+            if (is_file($root . $dir . $file)) {
+                return $dir . rawurlencode($file);
+            }
+        }
+    }
+    return is_file($root . $fallback) ? $fallback : '';
+}
+
 // ─── Email template loader ────────────────────────────────────────────────────
 // {{placeholder}} HTML bodies under templates/emails/. Built locally, delivered
 // by id.andmore.pt via the enqueue_email()/flush_message() façade.
@@ -132,9 +150,9 @@ function load_email_template(string $template, array $vars): string {
     }
     $html  = file_get_contents($path);
     $brand = htmlspecialchars(APP_NAME, ENT_QUOTES, 'UTF-8');
-    $logo  = (string) setting('logo_light_filename', '');
-    $logoTag = $logo !== ''
-        ? '<img src="' . htmlspecialchars(base_url('assets/img/logo/' . rawurlencode($logo)), ENT_QUOTES, 'UTF-8')
+    $rel   = site_logo_rel('logo_light_filename', 'site/assets/img/logos/logo_crossfit_white.svg');
+    $logoTag = $rel !== ''
+        ? '<img src="' . htmlspecialchars(base_url($rel), ENT_QUOTES, 'UTF-8')
             . '" alt="' . $brand . '" style="max-height:60px;border:0;">'
         : '<p style="margin:0;color:#fff;font-size:22px;font-weight:bold;letter-spacing:1px;">' . $brand . '</p>';
     $html = str_replace('{{logo_html}}', $logoTag, $html);