feat(editor): add WPCN JSON round-trip (export/import sidecar)

Closes the JSON round-trip gap on the player condition catalog
format shipped this batch. --export-wpcn-json emits all 11
scalar fields plus dual int + name forms for conditionKind /
comparisonOp / chainOp so hand-edits can use either
representation. --import-wpcn-json accepts either form,
falling back to the int when both are present. Verified
byte-identical round-trip on all three preset emitters
(starter / quest-gates / composite — including chained
conditions referencing other entries by chainNextId). 747
documented CLI flags.

tools/editor/cli_arg_required.cpp

@@ -146,6 +146,7 @@ const char* const kArgRequired[] = {
     "--export-wwui-json", "--import-wwui-json",
     "--gen-pcn", "--gen-pcn-quest-gates", "--gen-pcn-composite",
     "--info-wpcn", "--validate-wpcn",
+    "--export-wpcn-json", "--import-wpcn-json",
     "--gen-weather-temperate", "--gen-weather-arctic",
     "--gen-weather-desert", "--gen-weather-stormy",
     "--gen-zone-atmosphere",