AudioContent should have had a non-pointer receiver, to be consistent
with other content types. Add this to our log of rough edges to
reconsider for v2.
Fixes#641
Add initial support for URL mode elicitation, by introducing the new
types, as well as both server and client-side validation.
A follow-up CL will add support for ErrURLElicitationRequired.
For #623
Implement SEP 986, enforcing restrictions on tool names. Since we're
already at v1 we couldn't turn this into a panic, so use an error log
instead. This is consistent with the typescript SDK. A note is left in
our 'rough edges' doc to panic in v2.
Fixes#621
Start keeping a log of rough edges we've discovered post v1.0.0, so that
they're discoverable (along with their workarounds), and so that we can
fix them in v2.
