is_token looked only at the leading identifier, so on a workbook with a
sheet called Output (or Row, Column, or the name of a declared input),
"Output!A1:B2" was read as the Output token, and the step failed with
"the macro has no output anchor" or "unexpected '!A1:B2'". This hit
reference keys, $ref and {{...}} alike, including references the
recorder writes for other sheets. A base followed by '!' is now a sheet
name, and the text resolves as a plain reference.
Opening a workbook accepted a macro whose format version `v` was above MACRO_VERSION. Serde
dropped the fields this build doesn't know, and the next save wrote the reduced macro back
with `v: 2`, so a newer build would read it as a complete version 2 macro.
A version above MACRO_VERSION is now refused by Macro::check_limits, and parse_macro checks
the raw `v` before reading the steps. Such a macro takes the existing per-macro path: it is
left out with the usual single warning (which now names a newer format), and the rest of the
workbook opens. Tests cover JSON and xlsx hidden names, with current and missing versions as
controls.
prxnvt