feat: floating contact bar, remove pricing contact links, fix admin hooks

- Add FloatingContact bar (Записаться + Instagram) visible while scrolling
- Hides on hero and near contact section, centered at bottom
- Move BackToTop button up to avoid overlap
- Remove redundant ContactHint from Pricing section (floating bar covers it)
- Fix React hooks order violation in AdminLayout (early return before useEffect)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/ui/BackToTop.tsx

@@ -19,7 +19,7 @@ export function BackToTop() {
     <button
       onClick={() => window.scrollTo({ top: 0, behavior: "smooth" })}
       aria-label="Наверх"
-      className={`fixed bottom-6 right-6 z-40 flex h-10 w-10 items-center justify-center rounded-full border border-gold/30 bg-black/60 text-gold-light backdrop-blur-sm transition-all duration-300 hover:bg-gold/20 hover:border-gold/50 ${
+      className={`fixed bottom-20 right-6 z-40 flex h-10 w-10 items-center justify-center rounded-full border border-gold/30 bg-black/60 text-gold-light backdrop-blur-sm transition-all duration-300 hover:bg-gold/20 hover:border-gold/50 ${
         visible ? "translate-y-0 opacity-100" : "translate-y-4 opacity-0 pointer-events-none"
       }`}
     >

src/components/ui/FloatingContact.tsx

@@ -0,0 +1,65 @@
+"use client";
+
+import { useState, useEffect } from "react";
+import { Instagram } from "lucide-react";
+import { BRAND } from "@/lib/constants";
+import { SignupModal } from "./SignupModal";
+
+export function FloatingContact() {
+  const [visible, setVisible] = useState(false);
+  const [modalOpen, setModalOpen] = useState(false);
+
+  useEffect(() => {
+    function handleScroll() {
+      const contactEl = document.getElementById("contact");
+
+      const pastHero = window.scrollY > window.innerHeight * 0.7;
+      const reachedContact = contactEl
+        ? window.scrollY + window.innerHeight > contactEl.offsetTop + 100
+        : false;
+
+      setVisible(pastHero && !reachedContact);
+    }
+
+    window.addEventListener("scroll", handleScroll, { passive: true });
+    handleScroll();
+    return () => window.removeEventListener("scroll", handleScroll);
+  }, []);
+
+  return (
+    <>
+      <div
+        className={`fixed bottom-6 left-1/2 z-40 -translate-x-1/2 flex items-center gap-3 rounded-full border border-gold/20 bg-black/80 px-2 py-2 backdrop-blur-md shadow-lg shadow-black/40 transition-all duration-400 ${
+          visible
+            ? "translate-y-0 opacity-100"
+            : "translate-y-6 opacity-0 pointer-events-none"
+        }`}
+      >
+        <button
+          onClick={() => setModalOpen(true)}
+          className="rounded-full bg-gold px-5 py-2 text-sm font-semibold text-black transition-colors hover:bg-gold-light"
+        >
+          Записаться
+        </button>
+
+        <a
+          href={BRAND.instagram}
+          target="_blank"
+          rel="noopener noreferrer"
+          aria-label="Instagram"
+          className="flex h-9 w-9 items-center justify-center rounded-full border border-gold/30 text-gold-light transition-colors hover:bg-gold/20 hover:border-gold/50"
+        >
+          <Instagram size={18} />
+        </a>
+      </div>
+
+      <SignupModal
+        open={modalOpen}
+        onClose={() => setModalOpen(false)}
+        title="Записаться на занятие"
+        subtitle="Оставьте контактные данные и мы свяжемся с вами"
+        endpoint="/api/group-booking"
+      />
+    </>
+  );
+}