fix the import issue in environment

Author: BengeeL

backend/src/shared/config/environment.ts

@@ -1,4 +1,5 @@
 import dotenv from "dotenv";
+import { StringValue } from "ms";
 
 // Only load .env file in development; in production, Railway injects env vars automatically
 if (process.env.NODE_ENV !== "production") {
@@ -17,9 +18,9 @@ export const env = {
   jwt: {
     secret: process.env.JWT_SECRET || "default_secret",
     refreshSecret: process.env.JWT_REFRESH_SECRET || "refresh_default_secret",
-    expiresIn: (process.env.JWT_EXPIRES_IN as string) || "1d",
+    expiresIn: (process.env.JWT_EXPIRES_IN as StringValue) || "1d",
     refreshExpiresIn:
-      (process.env.JWT_REFRESH_EXPIRES_IN as string) || "30d",
+      (process.env.JWT_REFRESH_EXPIRES_IN as StringValue) || "30d",
   },
   ai: {
     geminiKey: process.env.GEMINI_API_KEY,