Update site content, styling, and review layout

Revise about page, hello world post, and The Compound review. Add book
cover support to review template, favicon, typographer config, and
cover image enrichment script.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

site/static/css/main.css

@@ -336,6 +336,14 @@ article hr {
 }
 
 /* ── Book review ───────────────────────────────── */
+.book-cover {
+  float: right;
+  width: 180px;
+  margin: 0 0 1rem 1.5rem;
+  border: 1px solid var(--border);
+  border-radius: 2px;
+}
+
 .book-meta {
   font-family: var(--font-mono);
   font-size: 0.75rem;
@@ -528,6 +536,13 @@ article hr {
     padding-top: 0;
   }
 
+  .book-cover {
+    float: none;
+    display: block;
+    width: 100px;
+    margin: 0 0 1.25rem 0;
+  }
+
   .book-meta {
     grid-template-columns: 1fr;
     gap: 0.5rem;