project_write checks versions it has seen and reads local files up to a size setting

What

The project_write tool lets Claude write project documents. A version is a value that identifies one state of a document.

• Writing over an existing document no longer reads it back and compares its text. Claude Code looks up the version from what the session has already seen and refuses the write if the if_version given does not match. This is behind two switches, tengu_lovely_rain and tengu_lucky_nebula.
• New failure codes: project_doc_stale, if_version_not_held and if_version_not_served.
• Reading a file from local_path now uses a size limit taken from a setting instead of a fixed cap. If refused, Claude is told to read the whole file again first, or pass its text as content.
• The Write tool checks for start-only files before writing.
• A .xlsx entry was added to the list of file types.

Why

Writes are guarded by version numbers rather than a text read-back, so a document changed by someone else is caught. The size of local files project_write will read is no longer fixed.