feat(editor): WAUH JSON round-trip closure

Adds --export-wauh-json / --import-wauh-json with the established
readEnumField template factoring int+name dual encoding for
factionAccess ("both"/"alliance"/"horde"/"neutral"). All 3
presets (stormwind/orgrimmar/bootybay) byte-identical binary
roundtrip OK including the Booty Bay neutral 15%/15% rate
configuration.

Live-tested economic-trap validator: hand-mutated Booty Bay
deposit to 60% + cut to 50% (sum 110%). Validator correctly
errored: "depositRatePct=6000 + cutPct=5000 = 11000 basis
points — seller would lose money on every sale (combined rates
>= 100%)". Catches misconfigured AH rates that would silently
trap players into negative expected returns on every listing.

CLI flag count 1452 -> 1454.

tools/editor/cli_arg_required.cpp

@@ -427,6 +427,7 @@ const char* const kArgRequired[] = {
     "--export-wprc-json", "--import-wprc-json",
     "--gen-auh-stormwind", "--gen-auh-orgrimmar", "--gen-auh-bootybay",
     "--info-wauh", "--validate-wauh",
+    "--export-wauh-json", "--import-wauh-json",
     "--gen-weather-temperate", "--gen-weather-arctic",
     "--gen-weather-desert", "--gen-weather-stormy",
     "--gen-zone-atmosphere",