All services: pass TZ to a container only when its image uses it

[jackspiering]

Follow-up to #356. This PR is stacked on that branch, so merge #356 first.

What changed

Every .env defines TZ. This PR makes compose.yaml match what each image does with it. TZ stays in every .env file.

Added TZ=${TZ} to the app container (28 services). These defined TZ in .env but never passed it on, and their image uses it:

Arcane, Booklore, Coder, ConvertX, copyparty, Dockge, Dockhand, Docmost, Dozzle, EspoCRM, FossFLOW, Glance, Gotify, Homepage, Memos, Miniflux, NewWallpaperWhoDis, NextExplorer, Portracker, Radicale, Speedtest Tracker, Stirling PDF, Sure (web and worker), Technitium, Tracktor, Uptime Kuma, Vaultwarden, XWiki.

Removed TZ=${TZ} from the app container (5 services). These images have no time zone data and log in UTC whatever the value:

Beszel Hub, Homebox, Navidrome, Portainer, RustDesk Server (hbbs and hbbr).

Behavior change

In the 28 services above, the app container now runs in the time zone from .env, which defaults to Europe/Amsterdam. Until now those containers ran in UTC. Log timestamps and anything the app schedules by local time shift accordingly. Set TZ in .env to your own zone, or to Etc/UTC to keep the old behavior.

How each image was checked

All 150 images used in the repo were pulled and started with TZ=Asia/Tokyo:

1. date +%Z_%z inside the image. 115 images reported JST_+0900.
2. For the rest, the runtime was checked, because it can carry its own time zone data: new Date().getTimezoneOffset() for Node.js images, the bundled JVM for Java images, and a search of the Go binary for embedded zone data.
3. Seven images that failed both (Beszel Hub, Beszel Agent, Homebox, Meilisearch, Navidrome, Portainer, RustDesk Server) were started with their normal entrypoint and their log timestamps were compared with UTC. All seven logged UTC. Ollama and the Tailscale image were judged on steps 1 and 2 only.

Left unchanged on purpose

• Beszel Agent, Ollama: the image does not use TZ, and compose.yaml did not pass it.
• Tailscale exit node, subnet router, app connector: the Tailscale image does not use TZ.
• Ghost: Node.js reads TZ, but Ghost forces UTC internally and has its own site time zone setting, so it is not passed.
• Seafile: uses its own TIME_ZONE variable.
• Karakeep: Meilisearch ignores TZ but receives it through env_file, so there is no line to remove.
• Database and cache containers: only app containers were changed.

Testing

• docker compose config --quiet passes in all 33 changed service directories.
• docker compose config resolves TZ to Europe/Amsterdam on each of the 29 containers that gained it, and no longer sets it on the 6 containers that lost it.
• git diff --check passes.

Not tested: the stacks were not started through a Tailnet. The images were only run on their own to check the time zone.