feat(storage): define StorageAdapter interface types + scaffold package

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

packages/storage/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "outDir": "dist",
+    "rootDir": "src"
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist"]
+}