feat(editor): add WLMA JSON round-trip (--export/--import-wlma-json)

Dual encoding for both modeKind fields (the primary
modeKind AND the timeoutFallbackKind disconnect-fallback)
via the readEnumField template — both accept int 0..5
OR token "freeforall"/"roundrobin"/"masterloot"/
"needbeforegreed"/"personal"/"disenchant".
masterLooterRequired accepts bool or int.

thresholdQuality serializes as both int (authoritative,
0..7) AND derived qualityName string ("Poor"/"Common"/
"Uncommon"/"Rare"/"Epic"/"Legendary"/"Artifact"/
"Heirloom") for human-readable JSON. The qualityName is
informational only — int form is authoritative on
import.

All 3 presets (standard/raid/afk) byte-identical
roundtrip OK. CLI flag count 1253 -> 1255.

tools/editor/cli_arg_required.cpp

@@ -364,6 +364,7 @@ const char* const kArgRequired[] = {
     "--export-wmar-json", "--import-wmar-json",
     "--gen-lma", "--gen-lma-raid", "--gen-lma-afk",
     "--info-wlma", "--validate-wlma",
+    "--export-wlma-json", "--import-wlma-json",
     "--gen-weather-temperate", "--gen-weather-arctic",
     "--gen-weather-desert", "--gen-weather-stormy",
     "--gen-zone-atmosphere",