Translates the script_author tool's error reasons into messages a worker can
act on. Called by YmerNode.Mcp.Tools.ScriptAuthor's
Wymcp.Tool.handle_error/1.
Two sources, and the split is worth knowing when you add a clause. The
compiler refuses code before a row exists — every reason
YmerNode.Scripts.Compiler can answer arrives here, and the detail it carries
is already the diagnostic, so most clauses add the next call and nothing else.
Acceptance refuses what the compiler cannot see, because it depends on the
other rows.
Deliberately not shared with YmerNode.Mcp.Tools.Scripts.Errors: nothing here
can reach that tool, which compiles nothing and accepts nothing, and nothing
there but :not_found can reach this one.