refactor(frontend): EmptyState + LoadingSkeleton primitives; unified ThoughtForm replaces PostThoughtForm and ReplyForm

thoughts-frontend/components/loading-skeleton.tsx

@@ -0,0 +1,34 @@
+import { Card, CardContent, CardHeader } from "@/components/ui/card"
+import { Skeleton } from "@/components/ui/skeleton"
+
+export function ThoughtSkeleton() {
+  return (
+    <Card>
+      <CardHeader className="flex flex-row items-center gap-4">
+        <Skeleton className="h-10 w-10 rounded-full" />
+        <div className="space-y-2">
+          <Skeleton className="h-4 w-32" />
+          <Skeleton className="h-3 w-20" />
+        </div>
+      </CardHeader>
+      <CardContent className="space-y-2">
+        <Skeleton className="h-4 w-full" />
+        <Skeleton className="h-4 w-4/5" />
+      </CardContent>
+    </Card>
+  )
+}
+
+export function ProfileSkeleton() {
+  return (
+    <Card>
+      <CardContent className="pt-6 flex items-center gap-4">
+        <Skeleton className="h-16 w-16 rounded-full" />
+        <div className="space-y-2">
+          <Skeleton className="h-5 w-40" />
+          <Skeleton className="h-4 w-24" />
+        </div>
+      </CardContent>
+    </Card>
+  )
+}