feat(bookwyrm): production-ready runtime + Redis wiring

- Dockerfile: build & install gunicorn wheels
- compose: run initdb before start; use `python -m gunicorn`
- env: add POSTGRES_* and BookWyrm Redis aliases (BROKER/ACTIVITY/CACHE) + CACHE_URL
- vars: add cache URL, DB indices, and URL aliases for Redis

Ref: https://chatgpt.com/share/68b7492b-3200-800f-80c4-295bc3233d68

roles/web-app-bookwyrm/templates/env.j2

@@ -22,17 +22,39 @@ EMAIL_HOST_PASSWORD="{{ EMAIL_HOST_PASSWORD }}"
 DEFAULT_FROM_EMAIL="{{ EMAIL_DEFAULT_FROM }}"
 
 # Database
+POSTGRES_DB="{{ database_name }}"
+POSTGRES_USER="{{ database_username }}"
+POSTGRES_PASSWORD="{{ database_password }}"
+POSTGRES_HOST="{{ database_host }}"
+POSTGRES_PORT="{{ database_port }}"
 DATABASE_URL="postgres://{{ database_username }}:{{ database_password }}@{{ database_host }}:{{ database_port }}/{{ database_name }}"
 
 # Redis / Celery
+REDIS_HOST="{{ BOOKWYRM_REDIS_HOST }}"
+REDIS_PORT="{{ BOOKWYRM_REDIS_PORT }}"
+REDIS_URL="{{ BOOKWYRM_REDIS_CACHE_URL }}"
+REDIS_CACHE_URL="{{ BOOKWYRM_REDIS_CACHE_URL }}"
+CACHE_URL="{{ BOOKWYRM_REDIS_CACHE_URL }}"
+DJANGO_REDIS_URL="{{ BOOKWYRM_REDIS_CACHE_URL }}"
+
+## Broker
+BROKER_URL="{{ BOOKWYRM_BROKER_URL }}"
 REDIS_BROKER_URL="{{ BOOKWYRM_REDIS_BROKER_URL }}"
-REDIS_CACHE_URL="{{ BOOKWYRM_REDIS_BASE_URL }}/1"
+REDIS_BROKER_HOST="{{ BOOKWYRM_REDIS_HOST }}"
+REDIS_BROKER_PORT="{{ BOOKWYRM_REDIS_PORT }}"
+REDIS_BROKER_DB_INDEX="{{ BOOKWYRM_REDIS_BROKER_DB }}"
 CELERY_BROKER_URL="{{ BOOKWYRM_REDIS_BROKER_URL }}"
 
+## Activity
+REDIS_ACTIVITY_HOST="{{ BOOKWYRM_REDIS_HOST }}"
+REDIS_ACTIVITY_PORT="{{ BOOKWYRM_REDIS_PORT }}"
+REDIS_ACTIVITY_DB_INDEX="{{ BOOKWYRM_REDIS_ACTIVITY_DB }}"
+REDIS_ACTIVITY_URL="{{ BOOKWYRM_REDIS_ACTIVITY_URL }}"
+
 # Proxy (if BookWyrm sits behind reverse proxy)
 FORWARDED_ALLOW_IPS="*"
 USE_X_FORWARDED_HOST="true"
-SECURE_PROXY_SSL_HEADER="HTTP_X_FORWARDED_PROTO,{{ WEB_PROTOCOL }}"
+SECURE_PROXY_SSL_HEADER="{{ (WEB_PORT == 443) | string | lower }}"
 
 # OIDC (optional – only if BOOKWYRM_OIDC_ENABLED)
 {% if BOOKWYRM_OIDC_ENABLED %}