feat(editor): add WTRD JSON round-trip (--export/--import-wtrd-json)

Dual encoding for both WTRD enums via the readEnumField
template: ruleKind (int 0..6 OR token "allowed"/
"forbidden"/"soulboundexception"/"crossfactionallowed"/
"levelgated"/"goldescrowmax"/"auditlogged") and
targetingFilter (int 0..4 OR token "anyplayer"/
"samerealmonly"/"samefactiononly"/"sameaccountonly"/
"gmonly").

itemCategoryFilter serializes as raw uint32 (it's a
WIT item-class bitmask — pretty-printing would
duplicate WIT's existing class-name table).
goldEscrowMaxCopper as uint64 to support the >4 billion
copper cap range (~430,000 gold) typical for high-
value AH-bypass trades.

All 3 presets (standard/admin/rmt) byte-identical
roundtrip OK. CLI flag count 1232 -> 1234.

tools/editor/cli_arg_required.cpp

@@ -355,6 +355,7 @@ const char* const kArgRequired[] = {
     "--export-wvox-json", "--import-wvox-json",
     "--gen-trd", "--gen-trd-admin", "--gen-trd-rmt",
     "--info-wtrd", "--validate-wtrd",
+    "--export-wtrd-json", "--import-wtrd-json",
     "--gen-weather-temperate", "--gen-weather-arctic",
     "--gen-weather-desert", "--gen-weather-stormy",
     "--gen-zone-atmosphere",