style(entropy-guide): use the app's real look — Settings wallpaper + Montserrat

Layer the page over /assets/img/bg-settings.webp (fixed, cover, with a
dim gradient so prose between glass panels stays readable) and load the
actual Montserrat Bold/ExtraBold faces from the node's own web root,
instead of the flat-black background the /architecture/ guide uses.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

neode-ui/public/entropy/index.html

@@ -37,7 +37,21 @@
 
   * { margin: 0; padding: 0; box-sizing: border-box; }
 
-  html { scroll-behavior: smooth; }
+  html { scroll-behavior: smooth; color-scheme: dark; }
+
+  /* The app's actual header font, served from the node's own web root */
+  @font-face {
+    font-family: 'Montserrat';
+    src: url('/assets/fonts/Montserrat/Montserrat-Bold.ttf') format('truetype');
+    font-weight: 700;
+    font-style: normal;
+  }
+  @font-face {
+    font-family: 'Montserrat';
+    src: url('/assets/fonts/Montserrat/Montserrat-ExtraBold.ttf') format('truetype');
+    font-weight: 800;
+    font-style: normal;
+  }
 
   body {
     font-family: 'Avenir Next', system-ui, -apple-system, sans-serif;
@@ -47,6 +61,23 @@
     font-size: 16px;
   }
 
+  /* The app's Settings wallpaper, with a dim gradient so prose between the
+     glass panels stays readable — same layering as the dashboard views. */
+  body::before {
+    content: '';
+    position: fixed;
+    inset: 0;
+    z-index: -2;
+    background: #000 url('/assets/img/bg-settings.webp') center center / cover no-repeat;
+  }
+  body::after {
+    content: '';
+    position: fixed;
+    inset: 0;
+    z-index: -1;
+    background: linear-gradient(to bottom, rgba(0, 0, 0, 0.45), rgba(0, 0, 0, 0.62));
+  }
+
   nav {
     position: fixed;
     top: 0; left: 0;