feat: standalone frontend uses production build instead of dev server (#862)

* feat: standalone frontend uses production build instead of dev server

Override web service in docker-compose.standalone.yml to build from
www/Dockerfile (multi-stage: deps → build → standalone runner) instead
of running pnpm dev with bind-mounted source.

* chore: move standalone compose TODO to Huly issue RFFR-46

* fix: add required env vars for standalone production frontend

The standalone web service (node server.js) has no bind-mounted .env
files and the base env_file (.env.local) has API_URL commented out.
Next.js standalone server can't auto-load .env files without them on
disk, so all required vars must be explicit in the compose override.

---------

Co-authored-by: Igor Loskutov <igor.loskutoff@gmail.com>

docker-compose.standalone.yml

@@ -76,6 +76,30 @@ services:
       DIARIZATION_BACKEND: modal
       DIARIZATION_URL: http://cpu:8000
 
+  web:
+    image: reflector-frontend-standalone
+    build:
+      context: ./www
+    command: ["node", "server.js"]
+    volumes: !reset []
+    environment:
+      NODE_ENV: production
+      # Browser-facing URLs (host-accessible ports)
+      API_URL: http://localhost:1250
+      WEBSOCKET_URL: ws://localhost:1250
+      SITE_URL: http://localhost:3000
+      # Server-side URLs (docker-network internal)
+      SERVER_API_URL: http://server:1250
+      KV_URL: redis://redis:6379
+      KV_USE_TLS: "false"
+      # Standalone: no external auth provider
+      FEATURE_REQUIRE_LOGIN: "false"
+      NEXTAUTH_URL: http://localhost:3000
+      NEXTAUTH_SECRET: standalone-local-secret
+      # Nullify partial auth vars inherited from base env_file
+      AUTHENTIK_ISSUER: ""
+      AUTHENTIK_REFRESH_TOKEN_URL: ""
+
   cpu:
     build:
       context: ./gpu/self_hosted