normalize all stacks to conventions

- VOL_PATH always defaults to /data; vscode/opencode VOL_PROJECTS nests it
- TZ defaults to America/Vancouver (was UTC in etherpad, ntfy, redis)
- compose section order fixed (volumes before environment, command after networks)
- all default secrets are the literal ChangeThisPassword (grep-friendly,
  users must change them); removed a real key from ollama sample.env
- sample.env synced with compose: missing vars added with defaults, dead vars removed
- invoiceninja_dev/openarchiver_dev: app services had no environment block,
  wired all sample.env vars through so the stacks actually work
- opencode: sample.env OLLAMA_HOST renamed to OLLAMA_HOST_URL to match compose
- TZ values unquoted consistently

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

zammad_dev/sample.env

@@ -8,7 +8,7 @@ ZAMMAD_PORT=8080
 POSTGRES_VERSION=17.5-alpine
 POSTGRES_DB=zammad_production
 POSTGRES_USER=zammad
-POSTGRES_PASS=zammad
+POSTGRES_PASS=ChangeThisPassword
 
 # Redis
 REDIS_VERSION=7.4.5-alpine
@@ -25,3 +25,14 @@ ELASTICSEARCH_JAVA_OPTS=-Xms1g -Xmx1g
 TZ=America/Vancouver
 NGINX_PORT=8080
 NGINX_SERVER_NAME=_
+BACKUP_TIME=03:00
+ELASTICSEARCH_HOST=zammad-elasticsearch
+ELASTICSEARCH_PORT=9200
+HOLD_DAYS=10
+MEMCACHE_SERVERS=zammad-memcached:11211
+POSTGRESQL_DB_CREATE=true
+POSTGRESQL_OPTIONS=?pool=50
+POSTGRES_HOST=zammad-postgresql
+POSTGRES_PORT=5432
+RAILS_TRUSTED_PROXIES="['127.0.0.1', '::1']"
+REDIS_URL=redis://zammad-redis:6379