v1: hero buttons should skip past #navigate to the first content section

On every v1 content page, the hero button ("Tell Me More...", or "Read T&Cs" on the terms page) smooth-scrolls to #navigate, the grid of Navigate buttons. It should skip past that grid to the page's first real content section.

Why

The content sections animate in via scrollex in assets/js/main.js. .items and .gallery blocks (and the $wrapper.children() sections) have top: '30vh', bottom: '30vh', so they only lose is-inactive once they reach the middle band of the viewport. When the hero button lands on #navigate, the next section sits too low to trigger. Its content stays hidden until you scroll a little further by hand, which is the annoying bit. Landing on the content section itself should put it inside the trigger band straight away.

The Navigate grid stays where it is and is still reachable by scrolling up. Only the hero button's target changes.

Scope

None of these pages has a #pages anchor (only sitemap.html does), so each page needs its own target: the first section after #navigate.

Out of scope: index.html already targets its first content section (#first), and travel.html / under_construction.html have no hero button.

Open question

Should the per-page anchors stay as they are, or should every page's first content section get a shared id (e.g. #content) so every hero button carries the same href? A shared id makes the pages uniform and future pages easier, but it means renaming ids that may already be deep-linked.

Acceptance

• Every hero button above targets the page's first content section.
• On each page, clicking the hero button reveals that section's animated content with no extra manual scroll, at desktop and at the 360px floor.
• sitemap.html's button label is revisited once it targets #pages ("Jump to Pages" becomes accurate again).

Follows from review on #68.

Start by checking the hero-button markup and target sections in the listed HTML pages, then read assets/js/main.js to understand the scrollex trigger behavior. Update each listed page to target its specified first content section, revisit sitemap.html's button label, and verify the animated section appears after clicking at desktop width and 360px.