feat(API-11): Route API calls through AgilitonAPI gateway

Add gateway-first pattern: when AGILITON_API_KEY is set, route all
external API calls through the gateway with X-API-Key auth. Falls back
to direct API access when gateway is unavailable.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

dist/index.d.ts

@@ -0,0 +1,10 @@
+#!/usr/bin/env node
+/**
+ * Confluence MCP Server
+ *
+ * Provides Confluence Cloud page CRUD and collaboration via Model Context Protocol.
+ * Tools: confluence_list_spaces, confluence_create_space, confluence_search,
+ *        confluence_get_page, confluence_create_page, confluence_update_page,
+ *        confluence_get_comments, confluence_add_comment
+ */
+export {};