refactor(api): migrate MCP listing from DeepNLP to PulseMCP service

- Updated imports to use PulseMCPSearchParams and PulseMCPService instead of DeepNLP equivalents
- Replaced DeepNLP API calls with PulseMCP API endpoints and parameters
- Modified cached MCP transformation to manual mapping for PulseMCP data format
- Enhanced error handling and retry logic in server tools retrieval
- Added PulseMCP API base URL constant for centralized configuration

This change switches the underlying MCP provider from DeepNLP to PulseMCP, ensuring compatibility with the new API while maintaining existing functionality for MCP listing and tool retrieval.

components/mcp/MCPMarketplaceModal.tsx

@@ -1,7 +1,7 @@
 "use client";
 
 import { useState, useEffect, useCallback, useMemo } from "react";
-import { X, Search, Filter, Package, Star, Download, Eye } from "lucide-react";
+import { X, Search, Filter, Package, Star, Eye } from "lucide-react";
 import { MCPProvider } from "@/lib/types/mcp";
 import { MCPCard } from "./MCPCard";
 import { MCPCategoryFilter } from "./MCPCategoryFilter";
@@ -22,7 +22,7 @@ export function MCPMarketplaceModal({
   const [searchTerm, setSearchTerm] = useState("");
   const [debouncedSearchTerm, setDebouncedSearchTerm] = useState("");
   const [sortBy, setSortBy] = useState<
-    "rating" | "downloads" | "name" | "recent" | "total_ratings" | "updated_at"
+    "rating" | "name" | "recent" | "total_ratings" | "updated_at"
   >("rating");
   const [sortOrder, setSortOrder] = useState<"asc" | "desc">("desc");
   const [selectedMCP, setSelectedMCP] = useState<MCPProvider | null>(null);
@@ -283,7 +283,6 @@ export function MCPMarketplaceModal({
                     className="px-3 py-2 bg-[var(--surface)] border border-[var(--border)] rounded-md text-sm"
                   >
                     <option value="rating">Por Avaliação</option>
-                    <option value="downloads">Por Downloads</option>
                     <option value="name">Por Nome</option>
                     <option value="recent">Mais Recentes</option>
                     <option value="total_ratings">Por Nº de Reviews</option>