The flag-before-subcommand recovery path emitted a Type: unknown_flag whose
detail only carried unknown_flags + command_path, diverging from
flagDidYouMean's unknown_flag detail (unknown, command_path, suggestions,
valid_flags). A consumer keyed on Type then saw two shapes for one Type.
Emit the same keys from both paths: add unknown (the offending flag; joined
when multiple), plus empty suggestions/valid_flags — the subcommand isn't
resolved at this point, so there is no meaningful flag universe to suggest
from, and the group's own flags would mislead. unknown_flags is retained as
the authoritative multi-flag field. Test locks the shared schema.
fc10338253