feat(site): per-gym SEO texts, event gym selector, hero/navbar polish

- Generated SEO titles/descriptions per gym; gym seo fields override each on its own
- Keywords, author, og:site_name, favicon and JSON-LD logo follow the gym
- CrossFit page 404s before output for gyms without a box
- Events: «Mostrar em» gym selector; event page uses its gym's brand
- Hero event button text colour from the event colour (--ev-on)
- Navbar bottom line stops at the other-gym head (--switch-w)
- Diagonal hero blur mask; remove the trial link

config/functions_events.php

@@ -15,6 +15,7 @@ function events_defaults(): array {
         'location' => '', 'event_starts_at' => null, 'event_ends_at' => null,
         'publish_from' => '', 'publish_until' => '', 'is_active' => 1,
         'cta_label' => '', 'cta_url' => '', 'show_lead_form' => 1,
+        'gym_id' => null,   // NULL = shown on every gym's homepage
     ];
 }
 
@@ -117,8 +118,8 @@ function db_events_create(PDO $pdo, array $data): int {
         INSERT INTO events
             (slug, title, subtitle, summary, description, hero_image, cor, location,
              event_starts_at, event_ends_at, publish_from, publish_until,
-             is_active, cta_label, cta_url, show_lead_form)
-        VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)
+             is_active, cta_label, cta_url, show_lead_form, gym_id)
+        VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)
     ");
     $stmt->execute([
         $d['slug'], $d['title'], $d['subtitle'], $d['summary'], $d['description'],
@@ -127,6 +128,7 @@ function db_events_create(PDO $pdo, array $data): int {
         str_replace('T', ' ', (string) $d['publish_from']),
         str_replace('T', ' ', (string) $d['publish_until']),
         (int) $d['is_active'], $d['cta_label'], $d['cta_url'], (int) $d['show_lead_form'],
+        $d['gym_id'] ? (int) $d['gym_id'] : null,
     ]);
     $__id = (int) $pdo->lastInsertId();
     audit_change($pdo, 'event', 'events', 'e_id', (int) $__id, 'create', null, 'title');
@@ -141,7 +143,7 @@ function db_events_update(PDO $pdo, int $id, array $data): bool {
             slug = ?, title = ?, subtitle = ?, summary = ?, description = ?,
             hero_image = ?, cor = ?, location = ?,
             event_starts_at = ?, event_ends_at = ?, publish_from = ?, publish_until = ?,
-            is_active = ?, cta_label = ?, cta_url = ?, show_lead_form = ?
+            is_active = ?, cta_label = ?, cta_url = ?, show_lead_form = ?, gym_id = ?
         WHERE e_id = ?
     ");
     $stmt->execute([
@@ -151,6 +153,7 @@ function db_events_update(PDO $pdo, int $id, array $data): bool {
         str_replace('T', ' ', (string) $d['publish_from']),
         str_replace('T', ' ', (string) $d['publish_until']),
         (int) $d['is_active'], $d['cta_label'], $d['cta_url'], (int) $d['show_lead_form'],
+        $d['gym_id'] ? (int) $d['gym_id'] : null,
         $id,
     ]);
     $__r = $stmt->rowCount() > 0;