Improve cross-domain tracking and add "Always" script category

Move linker config into gtag('config') call with accept_incoming and
decorate_forms for reliable cross-domain linking. Capture _gl parameter
in sessionStorage to preserve attribution across navigation. Add
referrer-based attribution replay fallback so GA4 reports source/medium
instead of (not set) when UTMs are absent. Add "Always" script category
that executes without waiting for consent.

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

admin/css/admin.css

@@ -28,6 +28,7 @@
 	color: #fff;
 }
 
+.att-cc-badge--always { background: #4CAF50; }
 .att-cc-badge--functional { background: #2196F3; }
 .att-cc-badge--analytics { background: #FF9800; }
 .att-cc-badge--marketing { background: #9C27B0; }