fix secret key lazy loading

Author: cherman23

src/lib/auth/auth.ts

@@ -11,8 +11,13 @@ export const config = {
     secure: process.env.NODE_ENV === 'production',
 };
 
-// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-export const secretKey = createSecretKey(process.env.JWT_SECRET!, 'utf-8');
+function getSecretKey() {
+    const jwtSecret = process.env.JWT_SECRET;
+    if (!jwtSecret) {
+        throw new Error('JWT_SECRET environment variable is required');
+    }
+    return createSecretKey(jwtSecret, 'utf-8');
+}
 
 export interface SessionPayload {
     userId: string;
@@ -25,7 +30,7 @@ export async function createSession(payload: SessionPayload) {
         .setIssuedAt()
         .setIssuer(config.issuer)
         .setExpirationTime(Math.floor(Date.now() / 1000) + config.expiration)
-        .sign(secretKey);
+        .sign(getSecretKey());
 
     const cookieStore = await cookies();
     cookieStore.set(config.cookieName, session, {
@@ -48,7 +53,7 @@ export async function verifySession(): Promise<SessionPayload | null> {
     }
 
     try {
-        const { payload } = await jwtVerify(session, secretKey, {
+        const { payload } = await jwtVerify(session, getSecretKey(), {
             issuer: config.issuer,
         });