feat: add MCP marketplace and custom scrollbar styles

Add comprehensive CSS styles for the MCP Marketplace interface, including card hover effects, responsive grid layout, modal backdrop blur, category badges, rating stars, install buttons, and loading animations. Also include custom scrollbar styling for the model selector to enhance user experience and visual consistency.

components/mcp/MCPSearchBar.tsx

@@ -0,0 +1,31 @@
+"use client";
+
+import { Search } from "lucide-react";
+
+interface MCPSearchBarProps {
+  value: string;
+  onChange: (value: string) => void;
+  onSearch: () => void;
+}
+
+export function MCPSearchBar({ value, onChange, onSearch }: MCPSearchBarProps) {
+  const handleKeyPress = (e: React.KeyboardEvent) => {
+    if (e.key === "Enter") {
+      onSearch();
+    }
+  };
+
+  return (
+    <div className="relative flex-1">
+      <Search className="absolute left-3 top-1/2 transform -translate-y-1/2 h-4 w-4 text-[var(--muted-foreground)]" />
+      <input
+        type="text"
+        value={value}
+        onChange={(e) => onChange(e.target.value)}
+        onKeyPress={handleKeyPress}
+        placeholder="Search MCPs..."
+        className="w-full pl-10 pr-4 py-2 bg-[var(--surface)] border border-[var(--border)] rounded-md text-sm focus:outline-none focus:ring-2 focus:ring-[var(--primary)] focus:border-transparent mcp-search-input"
+      />
+    </div>
+  );
+}