feat(design): JSM 전문 토큰 체계 + Pretendard 도입, kx 토큰 재매핑

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

package-lock.json

@@ -21,6 +21,7 @@
         "lunar-javascript": "^1.7.7",
         "next": "^16.2.6",
         "openai": "^6.21.0",
+        "pretendard": "^1.3.9",
         "react": "^19.2.6",
         "react-dom": "^19.2.6",
         "react-markdown": "^9.0.1",
@@ -7958,6 +7959,12 @@
         "node": ">= 0.8.0"
       }
     },
+    "node_modules/pretendard": {
+      "version": "1.3.9",
+      "resolved": "https://registry.npmjs.org/pretendard/-/pretendard-1.3.9.tgz",
+      "integrity": "sha512-PaQAADyLY5v4kYFwkpSJHbSSYIkiriY/1xXw75TKoZ9UQQqeU+tvP05yTdZAWibiIYoo8ZKtRv8PM7w0IaywSw==",
+      "license": "OFL-1.1"
+    },
     "node_modules/prop-types": {
       "version": "15.8.1",
       "resolved": "https://registry.npmjs.org/prop-types/-/prop-types-15.8.1.tgz",