Apply brand identity to the frontend (ink + bronze + paper)

Replaces the default black/gray with the docs/brand palette: warm ink text on paper surfaces, bronze accent, serif headings and the Origin-mark wordmark in the header, favicon, and the 'where it came from matters' tagline. Light/dark adapt via CSS vars (ink/paper flip); bronze and paper are constant. Tailwind v4 @theme exposes bronze/paper/ink tokens and the serif stack. Buttons/inputs/cards restyled to match; brand SVGs vendored into public/.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Signed-off-by: Justin Paul <justin@jpaul.me>

frontend/app/page.tsx

@@ -4,15 +4,17 @@ import { Button } from "@/components/ui/button";
 
 export default function Home() {
   return (
-    <div className="space-y-6">
-      <div className="space-y-2">
-        <h1 className="text-3xl font-bold">Provenance</h1>
-        <p className="text-neutral-600">
-          Trace where you come from — your family and your land — with every fact linked to a
-          source, on infrastructure you control.
+    <div className="space-y-8 py-4">
+      <div className="space-y-4">
+        <h1 className="text-4xl font-semibold tracking-tight sm:text-5xl">
+          Where it came from matters
+        </h1>
+        <p className="max-w-prose text-lg text-[var(--muted)]">
+          Trace where you come from — your family <span className="text-bronze">and</span> your
+          land — with every fact linked to a source, on infrastructure you control.
         </p>
       </div>
-      <div className="flex gap-3">
+      <div className="flex flex-wrap gap-3">
         <Link href="/register">
           <Button>Create an account</Button>
         </Link>