Agentic Resource Discovery (ARD) manifest

Discover An ARD manifest (/.well-known/ard.json, superseding /.well-known/ai-catalog.json in ARD v0.91) is a JSON document published at an origin's well-known path that inventories every agent-facing resource on that domain in a single fetch: MCP endpoints, SEP-2127 Server Cards, A2A Agent Cards, OpenAPI specifications, /llms.txt, and payment/auth metadata. It solves the multi-probe discovery problem by giving agents one canonical directory at Step 1 (Discover). Used by: ard, ai-catalog-well-known-file.