A configured Yggdrasil root answering 200 with a name outside the Minecraft charset (or an identity UUID that does not parse) was rejected one layer up in the handler: a silent 204 with no log line, and because the rejection returned instead of continuing, every source behind the broken one was unreachable for that login. The resolver already treats the same class (200 without a usable profile, non-200, unreachable) as skip + log + failed; the name/UUID screens lived above it and silently stopped the ladder instead.
Live on the audit box, a single sloppy root produced 204s with no trace anywhere, and [bad root, valid root] answered 204 where the valid root would have admitted the login; nothing else in the nano matrix (60 checks across input validation, canonical rewrite, premium rename, failure modes, failover, log discipline, properties relay) was red.
Screen both shapes inside resolveHasJoined, before a 200 can win: identity ids must parse, third-party names must match the charset. A bad answer is logged ('unusable profile name' / 'unparseable profile id'), skipped, and counted as failed — 503 when nothing else validates, and later sources get their turn. The handler's guards stay as the last line before anything leaves (comments updated).
Gates: gofmt, go vet, go test ./..., deploy/bootstrap_test.sh all clean. Green live (v0.0.0+fix55): the five bad-name cases and the two failover cases all pass; matrix rerun 60/60.
Lemon-miaow
9dad61f508