fix: match side-polygon-stats curved corners to reference hub

Correct pseudo-element border-radius direction and allow header overflow so side curves render.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/components/dashboard/DashboardHeader.tsx

@@ -53,7 +53,7 @@ export function DashboardHeader({
   ];
 
   return (
-    <header className="dashboard-header-bar shrink-0 overflow-hidden">
+    <header className="dashboard-header-bar shrink-0">
       <div className="side-left-group min-w-0 shrink-0">
         <span className="side-title-main main_tit flex shrink-0 items-center gap-[10px] text-[20px] font-bold tracking-[-0.5px] text-[#bad8ca]">
           <span>총괄기획실</span>

frontend/src/index.css

@@ -52,14 +52,14 @@ body,
 .header-stats-bar::before,
 .side-polygon-stats::before {
   left: -35px;
-  border-top-left-radius: 20px;
+  border-top-right-radius: 20px;
   box-shadow: 18px 0 #093023;
 }
 
 .header-stats-bar::after,
 .side-polygon-stats::after {
   right: -35px;
-  border-top-right-radius: 20px;
+  border-top-left-radius: 20px;
   box-shadow: -18px 0 #093023;
 }
 
@@ -93,6 +93,7 @@ body,
   justify-content: space-between;
   position: relative;
   z-index: 10;
+  overflow: visible;
   height: 48px;
   min-height: 48px;
   padding: 0 22px 0 20px;