Restructure hero: image at natural size overflowing, intro as text, no hard-coded copy

- views/partials/page-hero.php: removed the page-intro partial call. The
  intro is now rendered inline as a single .page-hero__intro div
  containing the editor-supplied intro text only (no hard-coded
  heading). The H1 is rendered with a dedicated .page-hero__heading
  class for typography control. Breadcrumbs + H1 + intro are in a
  single .page-hero__content container.
- views/partials/page-intro.php: deleted (no longer used).
- styles/blocks/page-hero.css: rewritten layout. The hero has a min-height
  of clamp(31rem, 38vw, 36rem). .page-hero__media is a foreground
  absolutely-positioned img on the right (no mask, no cover, no
  object-fit), with bottom: -10% so the image's bottom hangs over
  the bottom edge of the hero. The vector is positioned at
  bottom: clamp(1.5rem, 4vw, 3rem) with some spacing from the bottom
  edge, full-width on the left. Both elements stay above the content
  layer (z-index 10) and below the breadcrumb/title text. The H1 uses
  Quincy serif at clamp(2.5rem, 6vw, 4.5rem). The intro text is
  capped at 36rem to sit alongside the H1 without spanning the full
  hero width.
- tests/inner-page.spec.js: removed the now-obsolete
  .page-hero__intro-heading / .page-hero__intro-text assertions (the
  intro is a single text block now).

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

tests/inner-page.spec.js

@@ -61,10 +61,6 @@ test.describe("inner page layout", () => {
         // Heading is rendered inside the hero.
         await expect(hero.locator("h1").first()).toBeVisible();
 
-        // Intro contains a heading and a body paragraph.
-        await expect(intro.locator(".page-hero__intro-heading").first()).toBeVisible();
-        await expect(intro.locator(".page-hero__intro-text").first()).toBeVisible();
-
         // Page renders without JS errors.
         expect(pageErrors).toEqual([]);
     });