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>

posthog_dev/sample.env

@@ -5,7 +5,7 @@ POSTHOG_RESTART=unless-stopped
 
 # Core
 POSTHOG_SITE_URL=http://localhost:8000
-POSTHOG_SECRET_KEY=ChangeMeToALongRandomStringHere
+POSTHOG_SECRET_KEY=ChangeThisPassword
 
 # Database
 POSTHOG_DB_NAME=posthog
@@ -20,6 +20,11 @@ POSTHOG_CLICKHOUSE_PASSWORD=ChangeThisPassword
 # Email (optional)
 POSTHOG_EMAIL_HOST=
 POSTHOG_EMAIL_USER=
-POSTHOG_EMAIL_PASSWORD=
+POSTHOG_EMAIL_PASSWORD=ChangeThisPassword
 POSTHOG_EMAIL_PORT=587
 POSTHOG_EMAIL_TLS=true
+POSTHOG_CLICKHOUSE_IMAGE=clickhouse/clickhouse-server:24-alpine
+POSTHOG_KAFKA_IMAGE=docker.io/bitnami/kafka:3.7
+POSTHOG_PORT=8000
+POSTHOG_POSTGRES_IMAGE=postgres:15-alpine
+POSTHOG_REDIS_IMAGE=redis:7-alpine