Development record

The library add --text flag help reads 'the extracted text of a non-text document' (internal/surface/cli/source.go:320, docs/reference/cli/commands.md:3756), which reads as if the value is the text itself. source.Add reads the value as a path and refuses anything that is not a readable regular file with 'the extracted text is not a readable regular file' (internal/core/source/add.go:301-306).