Enrich the landing page with a bento grid and aurora atmosphere

Close the flat-vs-adaline gap by adding depth and motion to our product shots:
- bento: replace the flat stacked features with a varied 12-column grid (org
  chart, cost, office, messages, connectors, plus a local-first highlight card),
  each with a corner glow and hover
- showcase: a dark aurora "Set the goal" statement band (Newsreader serif over a
  drifting northern-lights glow) for a light -> dark -> light rhythm
- hero + footer: aurora glow staging behind the dashboard and under the CTA
- ui/aurora + globals: mint/teal/lime drift-animated glow tokens
- remove the superseded flat feature components

e2e green (12 passed); build verified.

landing/components/sections/showcase.tsx

@@ -0,0 +1,25 @@
+import { Container } from "../ui/container";
+import { Reveal } from "../ui/reveal";
+import { Aurora } from "../ui/aurora";
+
+export function Showcase() {
+  return (
+    <section className="relative overflow-hidden bg-[var(--band)] text-[var(--band-text)]">
+      <Aurora />
+      <Container className="relative py-24 md:py-32 lg:py-40">
+        <Reveal className="mx-auto max-w-4xl text-center">
+          <p className="eyebrow text-sm opacity-60">One human in the loop</p>
+          <h2 className="mt-6 font-serif text-[clamp(2.25rem,1.4rem+3.6vw,4.5rem)] font-light leading-[1.05] tracking-[-0.02em]">
+            Set the goal.
+            <br />
+            The company forms around it.
+          </h2>
+          <p className="mx-auto mt-6 max-w-[52ch] text-lg leading-relaxed opacity-75">
+            An AI CEO hires the roles the mission needs, delegates the work, and reports back — while you keep the final
+            say on every decision that matters.
+          </p>
+        </Reveal>
+      </Container>
+    </section>
+  );
+}