Mirror of the sheet-skill-spec change that fixes three places teaching
an invalid +table-put payload shape — the typed protocol only has
columns / data / dtypes / formats (no formula field) and must always
be wrapped in an outer {"sheets":[...]} envelope. write-cells and the
SKILL.md decision table previously used the wrong field names (type /
format) and pointed users at +table-put for formula writes, which the
shortcut can't actually accept.
Synced from upstream canonical via generate:cli + sync:cli.
79362a8fe8