AWS Gateway API domain name support rough edges

[rsyring]

• mu provision will work unless the cert gets ISSUED before a mu deploy takes place. A chicken/egg problem. Could solve it by not considering the gateway a provision but more of a setup, something that could be ran at provision and deploy time. Just put a check in to make sure the lambda exists. On the other hand, we could start deploying a HW lambda with the provision.
• gateway.delete() will error out on certificate deletion with a "in use" error message. Takes about a minute to resolve. Could add a retry.
• the idea with mu and environments is that everything could be duplicated as needed. But what happens if two devs try to provision/deploy an app with a domain name?

[rsyring]

Add domain-name = ... to mu.toml and then:

❯ mu domain-name show
Traceback (most recent call last):
  File "/home/rsyring/.cache/uv-venvs/poster-pkg/bin/mu", line 10, in <module>
    sys.exit(cli())
             ^^^^^
  File "/home/rsyring/.cache/uv-venvs/poster-pkg/lib/python3.12/site-packages/click/core.py", line 1442, in __call__
    return self.main(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/rsyring/.cache/uv-venvs/poster-pkg/lib/python3.12/site-packages/click/core.py", line 1363, in main
    rv = self.invoke(ctx)
         ^^^^^^^^^^^^^^^^
  File "/home/rsyring/.cache/uv-venvs/poster-pkg/lib/python3.12/site-packages/click/core.py", line 1830, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/rsyring/.cache/uv-venvs/poster-pkg/lib/python3.12/site-packages/click/core.py", line 1226, in invoke
    return ctx.invoke(self.callback, **ctx.params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/rsyring/.cache/uv-venvs/poster-pkg/lib/python3.12/site-packages/click/core.py", line 794, in invoke
    return callback(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/rsyring/.cache/uv-venvs/poster-pkg/lib/python3.12/site-packages/mu/cli/core.py", line 176, in domain_name
    pprint(gw.cert_describe())
           ^^^^^^^^^^^^^^^^^^
  File "/home/rsyring/.cache/uv-venvs/poster-pkg/lib/python3.12/site-packages/mu/libs/gateway.py", line 256, in cert_describe
    return self.acm_certs.client_describe(cert)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/rsyring/.cache/uv-venvs/poster-pkg/lib/python3.12/site-packages/mu/libs/gateway.py", line 80, in client_describe
    return self.b3c.describe_certificate(CertificateArn=rec.arn)['Certificate']
                                                        ^^^^^^^
AttributeError: 'NoneType' object has no attribute 'arn'