Add consent reopener: floating widget + anchor link trigger

Allow visitors to reopen the cookie preferences modal after making
their choice via a configurable floating button (bottom-right or
right-side vertical) or any anchor link with href="#att-cc-preferences".

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

includes/class-att-consent.php

@@ -29,8 +29,10 @@ class ATT_Consent {
 		'ga4_measurement_id' => '',
 		'gtm_container_id'   => '',
 		'consent_mode'       => 'advanced',
-		'banner_position'    => 'bottom',
-		'consent_expiry'     => 365,
+		'banner_position'        => 'bottom',
+		'consent_expiry'         => 365,
+		'floating_widget'        => 'bottom-right',
+		'floating_widget_label'  => 'Cookie Settings',
 
 		// Appearance.
 		'banner_bg_color'       => '#1a1a2e',