Fix mobile top spacing (double header offset) + CTA/newsletter gap

On mobile, body already has padding-top:60px to clear the fixed header, but
every page ALSO added its own clearance — doubling it and leaving a ~60px
white gap under the menu (content sat too low). Trimmed each page's mobile
top offset so it relies on the body padding (matching .article-page, which
was already correct): page-content, support/hub/legal pages, and the
news-hub / news-article / blog / member heroes. Content now sits ~32-42px
under the header.

Also add a 32px top gap to .newsletter-cta on mobile so it no longer
touches the CTA/content above it.

CSS only.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

css/pages/_hub.css

@@ -110,7 +110,7 @@
 
 /* ---------- Mobile ---------- */
 @media (max-width: 768px) {
-    .hub-page { padding-top: 60px; }
+    .hub-page { padding-top: 0; } /* body already offsets the fixed header on mobile */
     .hub-hero { padding: 40px 20px 32px; }
     .hub-hero h1 { font-size: 32px; }
     .hub-lead { font-size: 17px; line-height: 27px; }