chore:✅ add env validation

Author: nabadeep25

src/config/config.ts

@@ -1,6 +1,32 @@
 import dotenv from "dotenv";
+import Joi from "joi";
 dotenv.config({ path: ".env" });
 import { Dialect } from "sequelize";
+
+const envSchema = Joi.object({
+  DB_HOST: Joi.string().required(),
+  DB_PORT: Joi.number().required(),
+  DB_TYPE: Joi.string().valid("mysql", "postgres", "sqlite", "mariadb", "mssql").required(),
+  DB_NAME: Joi.string().required(),
+  DB_USER: Joi.string().required(),
+  DB_PASSWORD: Joi.string().required(),
+  SECRET: Joi.string().required(),
+  TOKEN_EXPIRY_HOUR: Joi.string().required(),
+  EMAIL_SERVICE: Joi.string().required(),
+  EMAIL_USER: Joi.string().required(),
+  EMAIL_PASS: Joi.string().required(),
+  EMAIL_FROM: Joi.string().required(),
+  OTP_EXPIRY_MIN: Joi.string().required(),
+  OTP_SECRET: Joi.string().required(),
+  NODE_ENV: Joi.string().valid("development", "production", "test").default("development"),
+  PORT: Joi.number().default(3000)
+}).unknown();
+
+const { error } = envSchema.validate(process.env);
+if (error) {
+  throw new Error(`Config validation error: ${error.message}`);
+}
+
 export const dbConfig = {
   host: process.env.DB_HOST,
   port: parseInt(process.env.DB_PORT, 10),