Startup failure due to invalid federation invite code and cascading deployment issues

[hensg]

In [3], if the application attempts to join a federation using an invite code linked to a shutdown or broken federation, the startup process will fail and trigger a crash in the main sequence. This failure cascades to [2] and subsequently to [1]. Given that the application supports dynamically adding or joining federations, it should not rely on an invite code for initial startup. Additionally, if a federation becomes inactive or is shut down after deployment, the previously used invite code may no longer be valid, potentially leading to failures in deployment configurations during a restart.

A workaround was added in [4] but it does not fix [1].

1. fedimint-clientd/fedimint-clientd/src/main.rs

   Line 102 in f2710e0

   let federation_id = state.multimint.register_new(invite_code).await?;

2. https://github.com/fedimint/fedimint-clientd/blob/master/multimint/src/lib.rs#L197
3. https://github.com/fedimint/fedimint-clientd/blob/master/multimint/src/lib.rs#L215-L218
4. https://github.com/fedimint/fedimint-clientd/blob/master/multimint/src/lib.rs#L180-L184