configファイルにAPP_ENVを追加

src/config.ts

@@ -1,3 +1,12 @@
+function getEnv() {
+  const e = process.env.REACT_APP_ENV;
+  if (e === "local") return e;
+  if (e === "staging") return e;
+  if (e === "production") return e;
+  return "other";
+}
+
+export const APP_ENV: "local" | "staging" | "production" | "other" = getEnv();
 // API
 // ----------------------------------------------------------------------
 export const HOST_API = process.env.REACT_APP_HOST_API_KEY || "";