A finding that stopped failing printed its internal key in the report
("Fixed: domain:example.org:spf:192.0.2.10"), and its CSV row had no
detail. Only the keys are kept between runs, so fixed_text() turns a key
back into a sentence ("Fixed: SPF for example.org didn't let 192.0.2.10
send"), in the past tense because a finding also goes when its address or
domain does. IPv6 addresses keep their colons; an unknown key prints as it
is.