chat-ui

d68a2a16 - revert(mcp): remove Exa direct integration, use mcp.exa.ai with server-side key injection (#2031)

revert(mcp): remove Exa direct integration, use mcp.exa.ai with server-side key injection (#2031) Reverts the direct Exa API integration in favor of using the standard mcp.exa.ai MCP server with server-side API key injection. Changes: - Remove exaDirect.ts (direct api.exa.ai client) - Remove Exa intercepts from httpClient.ts, tools.ts, health endpoint - Add isExaMcpServer() helper to hf.ts - Inject EXA_API_KEY as ?exaApiKey= URL param in runMcpFlow.ts and health endpoint The key is injected server-side via URL param because mcp.exa.ai doesn't support header-based authentication. Trade-off: Higher latency (~3-12s vs instant) but simpler maintenance using standard MCP protocol.