refactor(msg): single space between keyword and message, improve config suggestions

Tightens keyword formatting (ok/FAIL/hint/etc.) from two spaces to one.
Makes config key suggestions more generous: normalises spaces to
underscores, matches against leaf segments, and uses substring matching.
Updates all golden files.

testdata/cp-safe.ct

@@ -1,6 +1,6 @@
 $ pda set src@csf hello
 $ pda set dst@csf existing
 $ pda cp src@csf dst@csf --safe
-info  skipped 'dst@csf': already exists
+info skipped 'dst@csf': already exists
 $ pda get dst@csf
 existing