fix: enable cross-subdomain cookies for session sharing

src/lib/auth.ts

@@ -24,6 +24,20 @@ export const auth = betterAuth({
   session: {
     expiresIn: 60 * 60 * 24 * 7, // 7 days
     updateAge: 60 * 60 * 24, // Update session every day
+    cookieCache: {
+      enabled: true,
+      maxAge: 60 * 5, // 5 minutes
+    },
+  },
+  advanced: {
+    crossSubDomainCookies: {
+      enabled: true,
+      domain: process.env.COOKIE_DOMAIN || '.thenetwork.donovankelly.xyz',
+    },
+    defaultCookieAttributes: {
+      secure: true,
+      sameSite: 'none',
+    },
   },
   trustedOrigins: [
     process.env.APP_URL || 'http://localhost:3000',