Artifact read notes can say a version already counts as viewed

Artifacts are files Claude publishes, such as HTML pages. When Claude reads an artifact and its raw HTML is saved to disk, Claude gets a note about it. That note has changed in two ways:

• When Claude does not need to read the whole file, the note now says "this version counts as viewed".
• The note now ends with a short summary of the file, including its shape and how many lines it has.

Before, the note only ever said the version counted as viewed once Claude had read every line. Whether a read counts as viewed now also depends on whether the file has very long lines and on what Claude has already read.