feat(05-02): upgrade PageShell spacing to gap-8 and remove rounded-* from DashboardSkeleton

- PageShell: gap-6 → gap-8 for header-to-content spacing on all pages
- DashboardSkeleton: gap-6 → gap-8 (outer flex), gap-4 → gap-6 (summary cards), gap-6 → gap-8 (chart grid)
- DashboardSkeleton: remove rounded-md from 3 chart skeleton placeholders
- DashboardSkeleton: remove rounded-md from collapsible section row divs
- DashboardSkeleton: remove rounded-full from 2 badge skeleton placeholders

src/components/dashboard/DashboardSkeleton.tsx

@@ -17,22 +17,22 @@ function SkeletonStatCard() {
 
 export function DashboardSkeleton() {
   return (
-    <div className="flex flex-col gap-6">
+    <div className="flex flex-col gap-8">
       {/* Summary cards skeleton */}
-      <div className="grid gap-4 sm:grid-cols-2 lg:grid-cols-3">
+      <div className="grid gap-6 sm:grid-cols-2 lg:grid-cols-3">
         <SkeletonStatCard />
         <SkeletonStatCard />
         <SkeletonStatCard />
       </div>
 
       {/* 3-column chart area skeleton */}
-      <div className="grid gap-6 md:grid-cols-2 lg:grid-cols-3">
+      <div className="grid gap-8 md:grid-cols-2 lg:grid-cols-3">
         <Card>
           <CardHeader>
             <Skeleton className="h-5 w-40" />
           </CardHeader>
           <CardContent>
-            <Skeleton className="h-[250px] w-full rounded-md" />
+            <Skeleton className="h-[250px] w-full" />
           </CardContent>
         </Card>
         <Card>
@@ -40,7 +40,7 @@ export function DashboardSkeleton() {
             <Skeleton className="h-5 w-40" />
           </CardHeader>
           <CardContent>
-            <Skeleton className="h-[250px] w-full rounded-md" />
+            <Skeleton className="h-[250px] w-full" />
           </CardContent>
         </Card>
         <Card>
@@ -48,7 +48,7 @@ export function DashboardSkeleton() {
             <Skeleton className="h-5 w-40" />
           </CardHeader>
           <CardContent>
-            <Skeleton className="h-[250px] w-full rounded-md" />
+            <Skeleton className="h-[250px] w-full" />
           </CardContent>
         </Card>
       </div>
@@ -56,12 +56,12 @@ export function DashboardSkeleton() {
       {/* Collapsible sections skeleton */}
       <div className="space-y-3">
         {[1, 2, 3].map((i) => (
-          <div key={i} className="flex items-center gap-3 rounded-md border-l-4 border-muted bg-card px-4 py-3">
+          <div key={i} className="flex items-center gap-3 border-l-4 border-muted bg-card px-4 py-3">
             <Skeleton className="size-4" />
             <Skeleton className="h-4 w-32" />
             <div className="ml-auto flex items-center gap-2">
-              <Skeleton className="h-5 w-24 rounded-full" />
-              <Skeleton className="h-5 w-24 rounded-full" />
+              <Skeleton className="h-5 w-24" />
+              <Skeleton className="h-5 w-24" />
               <Skeleton className="h-4 w-16" />
             </div>
           </div>

src/components/shared/PageShell.tsx

@@ -12,7 +12,7 @@ export function PageShell({
   children,
 }: PageShellProps) {
   return (
-    <div className="flex flex-col gap-6">
+    <div className="flex flex-col gap-8">
       <div className="flex items-start justify-between gap-4">
         <div>
           <h1 className="text-2xl font-semibold tracking-tight">{title}</h1>