Artifact read results now show a REPL routing hint only when the REPL tool is available, plus a per-type 'two steps' note
When the Artifact tool renders the result of a read, it appends extra text explaining how to proceed. This routing text is now produced by a new function, fxn(), which first checks whether the Artifact REPL tool is present and returns nothing if it isn't, instead of always producing the text as before.
A second new helper, hur(), looks up a per-Artifact-type "two steps" routing note keyed by the file's frontmatter name, and reports whether the referenced files were kept as files. This feeds into flags used elsewhere to track how a read was handled.
This keeps the REPL-related guidance from appearing when the Artifact REPL tool (see related entries on AppifactRepl) isn't actually available in the session, and lets certain Artifact types show more specific two-step instructions after a read.