add feature to download catalog JSON from the agent or client

[wrenj]

just logging this idea, not sure if we need it in the near term

would be similar to agent card in a2a which can be downloaded at runtime but realistically is copy and pasted into code somewhere

for web can expose as a file
for clients on mobile would have to be added to the protocol somehow

[josemontespg]

A2UI Triage: I'm not sure I fully understand the feature request. @wrenj can you elaborate on the use case?