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-cross-store.ct

@@ -1,7 +1,7 @@
 # Cross-store copy
 $ pda set key@src value
 $ pda cp key@src key@dst
-  ok  copied key@src to key@dst
+  ok copied key@src to key@dst
 $ pda get key@src
 value
 $ pda get key@dst