fix: add extreme level tag

Author: Najeong-Kim

src/entities/slope/model/model.d.ts

@@ -1,4 +1,4 @@
-export type Level = '초급' | '초중급' | '중급' | '중상급' | '상급' | '최상급' | '파크';
+export type Level = '초급' | '초중급' | '중급' | '중상급' | '상급' | '최상급' | '파크' | '익스트림';
 
 export type SlopeRaw = {
   slopeId: number;

src/entities/slope/ui/level-chip.tsx

@@ -31,6 +31,10 @@ const LEVEL: Record<Level, { text: string; color: string }> = {
     text: '파크',
     color: 'bg-sub-2',
   },
+  익스트림: {
+    text: '익스트림',
+    color: 'bg-gray-70',
+  },
 };
 
 interface LevelChipProps {