feat(editor): add WEMO JSON round-trip (--export/--import-wemo-json)

Dual encoding for all 3 WEMO enums on import: emoteKind
(int OR "social"/"combat"/"roleplay"/"system"), sex
("both"/"male"/"female"), ttsHint ("talk"/"whisper"/"yell"/
"silent"). Reuses the readEnumField template pattern from
WMSP so the 3 enums share one parser body.

Also escapes a stray %s in the validate-wemo help text
that gcc -Wformat had been flagging as a missing-argument
warning. The literal "%s" appears inside the warning
description string so it must be encoded as %%s for
printf to render the helptext glyph correctly.

All 3 presets (basic/combat/rp) byte-identical roundtrip
OK. Token-form import smoke-tested with mixed roleplay +
female + whisper. CLI flag count 1131 -> 1133.

tools/editor/cli_arg_required.cpp

@@ -312,6 +312,7 @@ const char* const kArgRequired[] = {
     "--export-wmsp-json", "--import-wmsp-json",
     "--gen-emo", "--gen-emo-combat", "--gen-emo-rp",
     "--info-wemo", "--validate-wemo",
+    "--export-wemo-json", "--import-wemo-json",
     "--gen-weather-temperate", "--gen-weather-arctic",
     "--gen-weather-desert", "--gen-weather-stormy",
     "--gen-zone-atmosphere",