`sign_nip98` read the node's pubkey through `get_nostr_pubkey`, which goes
through `load_or_create_nostr_keys`. On a node with no Nostr identity that
does not fail — it GENERATES a keypair, writes the secret to disk, and signs
with it. So an IndeeHub auth header could quietly create a new node identity
as a side effect, then authenticate as a stranger holding a key nobody has
ever seen. The `.context("node has no Nostr identity")` guarding the call
could never fire, because the call could never fail that way.
`nostr_identity_exists` is the missing distinction: bootstrap may create,
but anything AUTHENTICATING as this node must prove the identity it already
has. sign_nip98 now gates on it and bails loudly.
Caught by `a_nip98_event_names_the_exact_url_and_method`, which asserts
exactly this ("must fail loudly rather than sign something empty") and had
been failing since the file landed in 58c759c1 — invisible because the
earlier runs on this branch filtered to `container::`.
Full bin suite 1381/1381.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
