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>

listmonk/sample.env

@@ -2,7 +2,7 @@
 POSTGRES_IMAGE=postgres:18.3-alpine
 POSTGRES_RESTART=unless-stopped
 POSTGRES_USER=listmonk
-POSTGRES_PASSWORD=securepassword
+POSTGRES_PASSWORD=ChangeThisPassword
 POSTGRES_DB=listmonk
 
 # Storage
@@ -22,7 +22,7 @@ TZ=America/Vancouver
 
 # Admin user
 LISTMONK_ADMIN_USER=admin
-LISTMONK_ADMIN_PASSWORD=changeme1234
+LISTMONK_ADMIN_PASSWORD=ChangeThisPassword
 
 # Hostname
 LISTMONK_HOSTNAME=listmonk.example.com