fix(server): register /.well-known/agent.json alias route in create_a2a_server#613

bokelley merged 2 commits intomainadcontextprotocol/adcp-client-python:mainfrom

claude/issue-612-a2a-alias-routeadcontextprotocol/adcp-client-python:claude/issue-612-a2a-alias-routeCopy head branch name to clipboard