Refactor admin layout and merchants page for improved UI and functionality; add URL copy feature and enhance date formatting

components/AdminLeftNavigation.tsx

@@ -46,9 +46,10 @@ export default function AdminLeftNavigation({
   return (
     <aside
       className={cx(
-        "sticky top-0 flex h-screen shrink-0 flex-col border-r border-zinc-900 bg-zinc-950/60 backdrop-blur",
+        "fixed left-0 flex shrink-0 flex-col border-r border-zinc-900 bg-zinc-950/60 backdrop-blur z-40",
         collapsed ? "w-[68px]" : "w-[280px]"
       )}
+      style={{ top: '52px', height: 'calc(100vh - 52px)' }}
     >
       {/* Header / Brand */}
       <div className={cx("flex items-center justify-between px-3 py-3", collapsed && "justify-center")}>

components/Banner.tsx

@@ -2,9 +2,9 @@ import React from "react";
 
 export function Banner() {
   return (
-    <div>
+    <div className="fixed top-0 left-0 right-0 z-50">
       {/* Early access bar */}
-      <div className="border-b border-amber-500/20 bg-amber-500/5">
+      <div className="border-b border-amber-500/20 bg-amber-500/5 backdrop-blur-sm">
         <div className="mx-auto flex max-w-6xl flex-col gap-1 px-4 py-2 text-[0.75rem] text-amber-100 md:flex-row md:items-center md:justify-between">
           <div className="flex items-center gap-2">
             <span className="rounded-sm bg-amber-500/20 px-2 py-0.5 text-[0.65rem] font-semibold uppercase tracking-[0.18em] text-amber-300">