feat: add @solisting/sdk package scaffold

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

package.json

@@ -1,21 +1,16 @@
 {
   "name": "solisting",
   "license": "ISC",
+  "private": true,
+  "workspaces": [
+    "sdk",
+    "app"
+  ],
   "scripts": {
     "lint:fix": "prettier */*.js \"*/**/*{.js,.ts}\" -w",
     "lint": "prettier */*.js \"*/**/*{.js,.ts}\" --check"
   },
-  "dependencies": {
-    "@anchor-lang/core": "^1.0.2"
-  },
   "devDependencies": {
-    "@types/bn.js": "^5.2.0",
-    "@types/chai": "^5.2.3",
-    "@types/mocha": "^10.0.10",
-    "chai": "^6.2.2",
-    "mocha": "^11.7.6",
-    "prettier": "^3.8.3",
-    "ts-mocha": "^11.1.0",
-    "typescript": "^6.0.3"
+    "prettier": "^3.8.3"
   }
 }