feat: implement DASHBOARD_ORIGIN for invite and email links, enhancing self-hosted configuration and updating related documentation

apps/api/src/config/dashboard-url.ts

@@ -0,0 +1,20 @@
+import { env } from './env';
+
+/**
+ * Returns the base URL for the dashboard app, used for invite links, email links, etc.
+ * When DASHBOARD_ORIGIN is set (e.g. self-hosted), it takes precedence.
+ * Otherwise: dev → localhost:5173, prod → app.classroomio.com (or subdomain for cloud).
+ */
+export function getDashboardBaseUrl(orgSiteName?: string): string {
+  if (env.DASHBOARD_ORIGIN) {
+    return env.DASHBOARD_ORIGIN.replace(/\/$/, '');
+  }
+
+  if (env.NODE_ENV === 'development') {
+    return 'http://localhost:5173';
+  }
+
+  const subdomain = orgSiteName || 'app';
+
+  return `https://${subdomain}.classroomio.com`;
+}

apps/api/src/config/env.ts

@@ -41,7 +41,9 @@ const envSchema = z.object({
   /** When 'true', instance runs in self-hosted mode: single org, auto-enroll as student, no org switching */
   PUBLIC_IS_SELFHOSTED: z.string().optional(),
   /** License key for enterprise features (SSO, token-auth, no-tracking, etc.) */
-  LICENSE_KEY: z.string().optional()
+  LICENSE_KEY: z.string().optional(),
+  /** Dashboard origin for invite/email links (e.g. https://app.yourdomain.com). When set, all email links point here instead of app.classroomio.com. Required for self-hosted. */
+  DASHBOARD_ORIGIN: z.string().optional()
 });
 
 export const env = envSchema.parse(process.env);