Rebuild navbar, hero, and feature sections in adaline style

- navbar: sticky, transparent to blur-on-scroll, wordmark + mono nav links +
  theme toggle + Download CTA, Reicon Menu/Xmark icons (components/layout)
- theme-toggle: Reicon Sun/Moon icons
- hero: meadow badge, tight Instrument Sans headline, Download + How-it-works
  CTAs, availability line, framed dashboard shot (components/sections)
- features: five stacked heading-over-panel sections mapping the org chart,
  office, messages, connectors and cost-control screens
- ui/media-frame: shared framed product-shot panel
- reveal: progressive enhancement — content is visible without JS and only
  hidden once the js class is present, then revealed on scroll
- remove the superseded flat navbar/hero/features components

Verified: next build green; desktop + mobile screenshots reviewed.

landing/components/sections/features.tsx

@@ -0,0 +1,15 @@
+import { Container } from "../ui/container";
+import { FeatureSection } from "./feature-section";
+import { featureSections } from "../../lib/landing-content";
+
+export function Features() {
+  return (
+    <section id="features" className="scroll-mt-20 py-20 md:py-28 lg:py-32">
+      <Container className="flex flex-col gap-24 md:gap-32">
+        {featureSections.map((feature) => (
+          <FeatureSection key={feature.id} feature={feature} />
+        ))}
+      </Container>
+    </section>
+  );
+}