feat(deploy): dockerize web app for portainer git-stack deploy behind external traefik

Add root Dockerfile (standalone Next output, multi-stage pnpm build), drop
in-stack caddy in favor of publishing web's port for an external traefik
LXC (file-provider dynamic config included), and document the portainer
deploy flow.

Also fixes issues that blocked any production build: a bad auth-client
type cast, the ai SDK's mimeType->mediaType rename, an implicit-any
callback param, and push.ts eagerly calling webpush.setVapidDetails at
module import time (which crashed page-data collection whenever VAPID
env vars weren't present at build) — now lazily configured on first send.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docker/compose.prod.yml

@@ -30,9 +30,29 @@ services:
     volumes:
       - minio_data:/data
     command: server /data --console-address ":9001"
+    healthcheck:
+      test: ["CMD", "mc", "ready", "local"]
+      interval: 5s
+      timeout: 5s
+      retries: 5
+
+  minio-init:
+    image: minio/mc:latest
+    depends_on:
+      minio:
+        condition: service_healthy
+    entrypoint: >
+      /bin/sh -c "
+        mc alias set local http://minio:9000 ${MINIO_ROOT_USER} ${MINIO_ROOT_PASSWORD};
+        mc mb --ignore-existing local/epicure-uploads;
+        mc anonymous set download local/epicure-uploads;
+        exit 0;
+      "
 
   web:
-    image: epicure-web:latest
+    build:
+      context: ..
+      dockerfile: Dockerfile
     restart: always
     environment:
       DATABASE_URL: postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@postgres:5432/${POSTGRES_DB}
@@ -43,35 +63,24 @@ services:
       STORAGE_BUCKET: epicure-uploads
       BETTER_AUTH_SECRET: ${BETTER_AUTH_SECRET}
       BETTER_AUTH_URL: ${BETTER_AUTH_URL}
+      ENCRYPTION_SECRET: ${ENCRYPTION_SECRET}
+      NEXT_PUBLIC_VAPID_PUBLIC_KEY: ${NEXT_PUBLIC_VAPID_PUBLIC_KEY}
+      VAPID_PRIVATE_KEY: ${VAPID_PRIVATE_KEY}
       GOOGLE_CLIENT_ID: ${GOOGLE_CLIENT_ID}
       GOOGLE_CLIENT_SECRET: ${GOOGLE_CLIENT_SECRET}
       OPENROUTER_API_KEY: ${OPENROUTER_API_KEY}
     ports:
-      - "3000:3000"
+      # published on portainer LXC host; traefik (other LXC) routes here via <this-lxc-ip>:${WEB_PORT}
+      - "${WEB_PORT:-3000}:3000"
     depends_on:
       postgres:
         condition: service_healthy
       redis:
         condition: service_started
       minio:
-        condition: service_started
-
-  caddy:
-    image: caddy:2-alpine
-    restart: always
-    ports:
-      - "80:80"
-      - "443:443"
-    volumes:
-      - ./Caddyfile:/etc/caddy/Caddyfile
-      - caddy_data:/data
-      - caddy_config:/config
-    depends_on:
-      - web
+        condition: service_healthy
 
 volumes:
   postgres_data:
   redis_data:
   minio_data:
-  caddy_data:
-  caddy_config: