Add EightX MCP Server — AI agent routing, identity & marketplace

[jshipman888]

Name: EightX
Description: The operating system for AI agents. Intelligent model routing across 12 AI providers, Agent Passports for cryptographic identity, and a marketplace of 50+ agent capabilities.
Endpoint: https://api.eightx.app/mcp
Discovery: https://api.eightx.app/.well-known/mcp.json
Auth: API key (X-Api-Key header) — get one at https://eightx.app/dashboard
Docs: https://eightx.app/docs#mcp
Tools: search_marketplace, get_agent, route_query, check_credits, issue_passport, notify_low_credits