style: update brand logo to user golden Celtic tree emblem

src/app/shell/Sidebar.tsx

@@ -74,14 +74,22 @@ export const Sidebar: React.FC = () => {
       {/* Brand Header */}
       <div className="h-14 px-3.5 flex items-center justify-between border-b border-[#3A3D35] bg-[#20221E]">
         <div className="flex items-center gap-2.5 overflow-hidden">
-          {/* Logo asset from public/branding/krona-logo.png */}
+          {/* Logo asset from public/branding/krona-symbol.png */}
           <img
-            src={collapsed ? '/branding/krona-symbol.png' : '/branding/krona-logo.png'}
+            src="/branding/krona-symbol.png"
             alt="Крона"
-            className={`object-contain transition-all duration-200 ${
+            className="w-8 h-8 object-contain shrink-0"
-              collapsed ? 'w-8 h-8' : 'h-8 max-w-[150px]'
-            }`}
           />
+          {!collapsed && (
+            <div className="flex flex-col min-w-0 leading-tight select-none">
+              <span className="text-sm font-bold tracking-wider text-[#E5B842] uppercase truncate">
+                Крона
+              </span>
+              <span className="text-[9px] uppercase tracking-widest text-[#B78335] font-semibold">
+                Business OS
+              </span>
+            </div>
+          )}
         </div>
 
         <button