feat(editor): add WVOX JSON round-trip (--export/--import-wvox-json)

Dual encoding for both WVOX enums via the readEnumField
template: eventKind (int 0..8 OR token "greeting"/
"aggro"/"death"/"queststart"/"questprogress"/
"questcomplete"/"goodbye"/"special"/"phase") and
genderHint (int 0..2 OR token "male"/"female"/"both").
volumeDb serializes as signed int8 since boss-call
clips use +5dB above ambient and quiet whisper clips
can use -10dB or lower.

transcript serializes as a plain JSON string —
operators editing the JSON sidecar can rewrite voice
transcripts for accessibility (TTS engines and chat-
bubble subtitles) without binary tooling.

All 3 presets (questgiver/boss/vendor) byte-identical
roundtrip OK. CLI flag count 1225 -> 1227.

tools/editor/cli_arg_required.cpp

@@ -352,6 +352,7 @@ const char* const kArgRequired[] = {
     "--export-wspv-json", "--import-wspv-json",
     "--gen-vox", "--gen-vox-boss", "--gen-vox-vendor",
     "--info-wvox", "--validate-wvox",
+    "--export-wvox-json", "--import-wvox-json",
     "--gen-weather-temperate", "--gen-weather-arctic",
     "--gen-weather-desert", "--gen-weather-stormy",
     "--gen-zone-atmosphere",