resourcepack: declare compatibility range from 1.21.6 to latest known

Pack.mcmeta now spans pack_format MIN_SUPPORTED_FORMAT (=63, 1.21.6) up to
max(LATEST_KNOWN_FORMAT, resolved.format) so a single build loads on every
MC from 1.21.6 through 26.1.2+ (currently extending to 86 = 26.2). Both
schemas are written: supported_formats for clients on pack_format <= 64,
and min_format/max_format for 1.21.9+ clients. pack_format itself stays
at the build target so newer clients see the pack as current rather than
legacy.

locales/installer-rp/ko-kr.json

@@ -89,6 +89,7 @@
     "baseShaderOverrideStripped": "베이스 리소스팩의 vanilla 셰이더 오버라이드 제거: assets/minecraft/shaders/{{path}} — mcVersion {{mc}} (pack_format {{format}}) 의 새 GLSL API 와 호환되지 않아 결과 zip 에서 제외했습니다.",
     "packFormatMatched": "pack_format = {{format}} (mcVersion {{matched}})",
     "packFormatFallback": "pack_format = {{format}} (mcVersion \"{{version}}\" 매칭 실패, 최신 폴백)",
+    "packFormatRange": "호환 범위 선언: pack_format {{min}} ~ {{max}} (supported_formats / min_format / max_format 모두 기록)",
     "soundsMerged": "기존 sounds.json 병합 ({{count}}개 항목)",
     "ytdlpLine": "yt-dlp> {{line}}"
   },