diff --git a/apps/mana/apps/web/src/hooks.server.ts b/apps/mana/apps/web/src/hooks.server.ts
index 5c3ee4325..31b249e23 100644
--- a/apps/mana/apps/web/src/hooks.server.ts
+++ b/apps/mana/apps/web/src/hooks.server.ts
@@ -27,6 +27,8 @@ import { setSecurityHeaders } from '@mana/shared-utils/security-headers';
 
 const PUBLIC_MANA_AUTH_URL_CLIENT =
 	process.env.PUBLIC_MANA_AUTH_URL_CLIENT || process.env.PUBLIC_MANA_AUTH_URL || '';
+const PUBLIC_AUTH_WEB_URL_CLIENT =
+	process.env.PUBLIC_AUTH_WEB_URL_CLIENT || process.env.PUBLIC_AUTH_WEB_URL || '';
 const PUBLIC_GLITCHTIP_DSN = process.env.PUBLIC_GLITCHTIP_DSN || '';
 
 const PUBLIC_SYNC_SERVER_URL_CLIENT =
@@ -227,6 +229,7 @@ export const handle: Handle = async ({ event, resolve }) => {
 		transformPageChunk: ({ html }) => {
 			const envScript = `<script>
 window.__PUBLIC_MANA_AUTH_URL__ = ${JSON.stringify(PUBLIC_MANA_AUTH_URL_CLIENT)};
+window.__PUBLIC_AUTH_WEB_URL__ = ${JSON.stringify(PUBLIC_AUTH_WEB_URL_CLIENT)};
 window.__PUBLIC_SYNC_SERVER_URL__ = ${JSON.stringify(PUBLIC_SYNC_SERVER_URL_CLIENT)};
 window.__PUBLIC_ULOAD_SERVER_URL__ = ${JSON.stringify(PUBLIC_ULOAD_SERVER_URL_CLIENT)};
 window.__PUBLIC_MANA_MEDIA_URL__ = ${JSON.stringify(PUBLIC_MANA_MEDIA_URL_CLIENT)};
diff --git a/apps/mana/apps/web/src/lib/auth/portal-redirect.ts b/apps/mana/apps/web/src/lib/auth/portal-redirect.ts
index 394c5c975..48c556c1b 100644
--- a/apps/mana/apps/web/src/lib/auth/portal-redirect.ts
+++ b/apps/mana/apps/web/src/lib/auth/portal-redirect.ts
@@ -6,20 +6,33 @@
  * User auf `/auth/callback?next=…`, wo der Token via SSO-Cookie geholt
  * und der Encryption-Vault entsperrt wird.
  *
- * In Dev: `PUBLIC_AUTH_WEB_URL=http://localhost:3002`.
- * In Prod: `PUBLIC_AUTH_WEB_URL=https://auth.mana.how`.
- *
  * Diese Funktion macht einen harten `window.location.href` — keinen
  * SvelteKit-`goto` — weil das Portal eine eigene Origin ist.
+ *
+ * Resolution-Order für die Portal-URL:
+ *   1. `window.__PUBLIC_AUTH_WEB_URL__` (SSR-injected, prod: `https://auth.mana.how`)
+ *   2. `process.env.PUBLIC_AUTH_WEB_URL` (SSR)
+ *   3. `https://auth.mana.how` (default — auch in localhost ungewöhnlich)
+ *
+ * Wie bei `auth-fetch.authBaseUrl` lesen wir NICHT direkt
+ * `$env/dynamic/public` — die Build-Time-Env in Production wäre evtl.
+ * eine Docker-interne URL.
  */
 
-import { env as publicEnv } from '$env/dynamic/public';
+import { browser } from '$app/environment';
 
 const FALLBACK_PORTAL = 'https://auth.mana.how';
 const APP_ID = 'mana';
 
 function portalUrl(): string {
-	return publicEnv.PUBLIC_AUTH_WEB_URL ?? FALLBACK_PORTAL;
+	if (browser && typeof window !== 'undefined') {
+		const injected = (window as unknown as { __PUBLIC_AUTH_WEB_URL__?: string })
+			.__PUBLIC_AUTH_WEB_URL__;
+		return (injected || FALLBACK_PORTAL).replace(/\/$/, '');
+	}
+	const fromEnv =
+		(typeof process !== 'undefined' && process.env?.PUBLIC_AUTH_WEB_URL) || FALLBACK_PORTAL;
+	return fromEnv.replace(/\/$/, '');
 }
 
 function appOrigin(): string {
diff --git a/apps/mana/apps/web/src/lib/auth/session.svelte.ts b/apps/mana/apps/web/src/lib/auth/session.svelte.ts
index 220885acf..39d9907c4 100644
--- a/apps/mana/apps/web/src/lib/auth/session.svelte.ts
+++ b/apps/mana/apps/web/src/lib/auth/session.svelte.ts
@@ -30,15 +30,24 @@
  * Session vorhält.
  */
 
-import { env as publicEnv } from '$env/dynamic/public';
+import { authBaseUrl as resolveAuthBaseUrl } from '$lib/data/scope/auth-fetch';
 
 const TOKEN_KEY = 'mana.auth.accessToken';
 const USER_KEY = 'mana.auth.user';
 
-const FALLBACK_AUTH_URL = 'https://auth.mana.how';
-
+/**
+ * Mana-Auth-API-URL.
+ *
+ * Resolution-Order (siehe `auth-fetch.authBaseUrl`):
+ *   1. `window.__PUBLIC_MANA_AUTH_URL__` (SSR-injected, prod: `https://auth.mana.how`)
+ *   2. `process.env.PUBLIC_MANA_AUTH_URL` (SSR)
+ *   3. `http://localhost:3001` (dev fallback)
+ *
+ * KEIN `$env/dynamic/public` direkt — die Build-Time-Env in Production
+ * ist `http://mana-auth:3001` (Docker-internal, vom Browser unerreichbar).
+ */
 function authBaseUrl(): string {
-	return publicEnv.PUBLIC_MANA_AUTH_URL ?? FALLBACK_AUTH_URL;
+	return resolveAuthBaseUrl();
 }
 
 export interface SessionUser {
diff --git a/docker-compose.macmini.yml b/docker-compose.macmini.yml
index c54d712fd..1961dd57e 100644
--- a/docker-compose.macmini.yml
+++ b/docker-compose.macmini.yml
@@ -895,6 +895,13 @@ services:
       PORT: 5000
       PUBLIC_MANA_AUTH_URL: http://mana-auth:3001
       PUBLIC_MANA_AUTH_URL_CLIENT: https://auth.mana.how
+      # Auth-Portal-UI (mana-auth-web). In Prod gleiche Origin wie
+      # mana-auth API — nginx splittet `/api/*` (mana-auth) von den
+      # UI-Routen `/login`, `/register`, `/auth/callback` (mana-auth-web).
+      # Client-Code liest die `_CLIENT`-Variante via hooks.server.ts
+      # injection (`window.__PUBLIC_AUTH_WEB_URL__`).
+      PUBLIC_AUTH_WEB_URL: https://auth.mana.how
+      PUBLIC_AUTH_WEB_URL_CLIENT: https://auth.mana.how
       PUBLIC_SYNC_SERVER_URL: http://mana-sync:3010
       PUBLIC_SYNC_SERVER_URL_CLIENT: https://sync.mana.how
       # Unified Hono/Bun API server (apps/api) — hosts all 16 product