Interface ExplainCommandReading

ABSENT rather than refused where no attempt was made — the same convention transport follows. Statements always carry it; a […] subcommand does not, because its inner text has its own coordinate space that phase 1 does not rebase (see ExplainSubcommand).

args is present exactly when arguments read: it is that reading's object view (last occurrence wins), in the ratified sketch's place (commands/explain/README.md → Result shape). Absent is not {} — a command with no arguments reads as {}.

Present on document statements after the #202c-2 transport pass. Absent on subcommands, whose inner argument coordinates phase 1 does not rebase.