feat: chat reactions

components/layout/site-bottom-nav.tsx

@@ -19,6 +19,7 @@ import {
   useChatUnread,
 } from "@/components/layout/nav-unread-badge";
 import { useAuth } from "@/components/auth/auth-provider";
+import { useHidesAppChrome } from "@/lib/use-chrome-visibility";
 import { cn } from "@/lib/utils";
 
 type Item = {
@@ -31,6 +32,7 @@ type Item = {
 
 export function SiteBottomNav() {
   const pathname = usePathname();
+  const hidden = useHidesAppChrome();
   const { user } = useAuth();
   // Read here rather than inside the badge so the count can also reach the
   // link's accessible name — the badge itself is decorative.
@@ -97,6 +99,9 @@ export function SiteBottomNav() {
     return pathname === item.href || pathname.startsWith(`${item.href}/`);
   }
 
+  // A chat thread owns the bottom edge — its composer lives there.
+  if (hidden) return null;
+
   return (
     <nav
       aria-label="Primary"