Add logo rebrand: brand marks, logo page, and brand assets

stack-folder/folder.css

@@ -485,6 +485,14 @@ a.site-preview:hover {
   margin-bottom: 0.35rem;
 }
 
+.brand-mark {
+  display: block;
+  width: 2.25rem;
+  height: 2.25rem;
+  margin: 0 0 0.45rem;
+  border-radius: 0.45rem;
+}
+
 .body h1 {
   font-family: var(--display);
   font-size: 1.35rem;

stack-folder/index.html

@@ -41,6 +41,7 @@
       <div class="body body--has-preview">
         <div class="body-copy">
           <p class="file-id">LK-SPEC-1.0 · Cover sheet</p>
+          <img class="brand-mark" src="/favicon.svg" width="36" height="36" alt="" />
           <h1>Levkin</h1>
           <p class="tagline">Custom software, automation &amp; AI workflows</p>
           <p class="lead">Custom apps, automation, AI workflows, CaseWare, and QA — <span class="hi">scoped</span>, <span class="hi">production-ready</span>, and easy to <span class="hi">hand off</span>.</p>