Fix CORS error for PWA manifest by splitting Traefik routing

Split routing into two routers with different priorities:
- Public router (priority 100) handles PWA resources without authentication
- Protected router (priority 10) handles application routes with Authentik

Add CORS middleware for public PWA resources to allow cross-origin access
to manifest.webmanifest, service worker, and icons.

Fixes intermittent ERR_FAILED 302 and CORS errors when loading PWA manifest
from authenticated sessions.

docker-compose.yml

@@ -20,20 +20,34 @@ services:
       - "traefik.enable=true"
       - "traefik.docker.network=traefik-network"
 
-      # HTTP Router
+      # Service (shared by both routers)
+      - "traefik.http.services.${APP_NAME}.loadbalancer.server.port=3000"
+
+      # Router 1: Public PWA resources (no auth) - Higher priority
+      - "traefik.http.routers.${APP_NAME}-public.rule=Host(`${APP_DOMAIN}`) && (PathPrefix(`/manifest.webmanifest`) || PathPrefix(`/sw.js`) || PathPrefix(`/workbox-`) || PathPrefix(`/icon-`) || PathPrefix(`/apple-touch-icon`) || PathPrefix(`/favicon.ico`) || PathPrefix(`/robots.txt`))"
+      - "traefik.http.routers.${APP_NAME}-public.entrypoints=websecure"
+      - "traefik.http.routers.${APP_NAME}-public.tls.certresolver=letsencrypt"
+      - "traefik.http.routers.${APP_NAME}-public.priority=100"
+      - "traefik.http.routers.${APP_NAME}-public.service=${APP_NAME}"
+      - "traefik.http.routers.${APP_NAME}-public.middlewares=${APP_NAME}-headers,${APP_NAME}-cors"
+
+      # Router 2: Protected application (with auth) - Normal priority
       - "traefik.http.routers.${APP_NAME}.rule=Host(`${APP_DOMAIN}`)"
       - "traefik.http.routers.${APP_NAME}.entrypoints=websecure"
       - "traefik.http.routers.${APP_NAME}.tls.certresolver=letsencrypt"
-
-      # Service
-      - "traefik.http.services.${APP_NAME}.loadbalancer.server.port=3000"
-
-      # Middleware chain: Authentik Forward Auth + Headers
+      - "traefik.http.routers.${APP_NAME}.priority=10"
+      - "traefik.http.routers.${APP_NAME}.service=${APP_NAME}"
       - "traefik.http.routers.${APP_NAME}.middlewares=authentik-forward-auth@file,${APP_NAME}-headers"
 
       # Custom headers middleware
       - "traefik.http.middlewares.${APP_NAME}-headers.headers.customrequestheaders.X-Forwarded-Proto=https"
 
+      # CORS middleware for public resources
+      - "traefik.http.middlewares.${APP_NAME}-cors.headers.accesscontrolallowmethods=GET,OPTIONS"
+      - "traefik.http.middlewares.${APP_NAME}-cors.headers.accesscontrolalloworiginlist=https://${APP_DOMAIN}"
+      - "traefik.http.middlewares.${APP_NAME}-cors.headers.accesscontrolmaxage=100"
+      - "traefik.http.middlewares.${APP_NAME}-cors.headers.addvaryheader=true"
+
 networks:
   principal:
     external: true