Expand terminal filesystem, add mainframe hint cron, redirect PHP logs

- Game1 terminal: flesh out the virtual filesystem with a realistic
  spread of Linux directories/files (~70 dirs, ~140 files) so it no
  longer reads as an obviously small puzzle set, without touching any
  win-condition or rapport files.
- Add app:hints:check command + a php-cron container (BusyBox crond)
  that nudges players who haven't contacted every teammate 5 minutes
  into a session, via a new 'hint' Mercure message type.
- Log the cron command's output to var/log/cron/cron.log and rotate
  it (25MB / 90 days) via logrotate, run daily from the same crontab.
- Redirect PHP's error_log and Symfony's prod app/deprecation logs
  from stderr-only into var/log/php/*.log (kept alongside stderr),
  with the same rotation policy.

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

docker/compose.yaml

@@ -66,6 +66,39 @@ services:
     #     ipv4_address: 172.23.0.11
     restart: unless-stopped
 
+  php-cron:
+    build:
+      context: ..
+      dockerfile: docker/php/Dockerfile
+      args:
+        USER_ID: ${USER_ID}
+        GROUP_ID: ${GROUP_ID}
+    container_name: escapepage-php-cron
+    volumes:
+      - ../:/var/www/html:delegated
+      - /etc/hosts:/etc/hosts:ro
+    environment:
+      APP_ENV: ${APP_ENV}
+      SITE_BASE_URL: ${SITE_BASE_URL}
+      MAILER_DSN: ${MAILER_DSN}
+      MAILER_FROM: ${MAILER_FROM}
+      DATABASE_URL: ${DATABASE_URL}
+      MERCURE_URL: ${MERCURE_URL}
+      MERCURE_PUBLIC_URL: ${MERCURE_PUBLIC_URL}
+      MERCURE_JWT_SECRET: ${MERCURE_JWT_SECRET}
+      MERCURE_CORS_ALLOWED_ORIGINS: ${MERCURE_CORS_ALLOWED_ORIGINS}
+      MERCURE_TOPIC_BASE: ${MERCURE_TOPIC_BASE}
+      RECAPTCHA3_KEY: ${RECAPTCHA3_KEY}
+      RECAPTCHA3_SECRET: ${RECAPTCHA3_SECRET}
+    depends_on:
+      - database
+      - mercure
+    command: ["crond", "-f", "-l", "2"]
+    # networks:
+    #   backend:
+    #     ipv4_address: 172.23.0.16
+    restart: unless-stopped
+
   nginx:
     image: nginx:1.29.4-alpine
     container_name: escapepage-nginx