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/import-stdin.ct

@@ -2,7 +2,7 @@
 $ pda set existing@stn keep-me
 $ fecho dumpfile {"key":"new","value":"hello","encoding":"text"}
 $ pda import stn < dumpfile
-  ok  restored 1 entries into @stn
+  ok restored 1 entries into @stn
 $ pda get existing@stn
 keep-me
 $ pda get new@stn