feat(marketing-site): American Dream cover band + narrative weave

- Cover: publisher-style belly band across the lower book cover using a
  compressed banner (2.2MB screenshot -> 60KB WebP, resized to display
  needs), cropped via a width-locked <img> + percentage offset so the
  wordmark stays legible rather than getting zoomed/cropped sideways.
  Compass + wordmark compacted into a row to make room.
- Copy: the theme woven through Field Notes, Contents, the Founding
  Sponsor tier, and one direct FAQ entry -- mostly oblique, since the
  cover already states it explicitly. Hero/Recipe/Capture/Footer left
  untouched on purpose.

marketing-site/components/Contents.jsx

@@ -12,7 +12,7 @@ export default function Contents() {
     <section className="section contents" id="contents">
       <div className="wrap">
         <span className="spec reveal">The founding library</span>
-        <h2 className="reveal">Six practices. Written by people who do the work.</h2>
+        <h2 className="reveal">Six practices, written by people who built their careers on them.</h2>
         <div className="toc reveal">
           {ITEMS.map((x) => (
             <a href="#get" key={x.num}>