Options drained out of the pre-0.38.0 `DOCKER_OPTIONS_<PHASE>` files were copied verbatim rather than re-serialized the way `docker-options:add` stores them, so `docker-options:remove` compared the canonical string it builds against a stored value that could never match it and exited successfully without removing anything. Removal now matches stored options by shell word, and stored options are rewritten into the canonical form once on upgrade, which additionally splits an entry that carried several flags on a single line into one entry per flag so a single flag can be removed and so the readers that match on a flag prefix see one value per entry. The leftover `.migrated` sentinel drain is restored to running ahead of the global short-circuit that had made it unreachable, and the plugin's Go tests are added to the test target that had never run them.
Values supplied through docker options, `--ttl-seconds`, and `-e` flowed into a Bash `eval` during build, deploy, and run, letting a low-privileged user execute arbitrary commands on the host as the dokku user. These arguments are now tokenized and passed through to the container verbatim, without shell expansion. A one-time migration repairs stored labels whose backticks were saved with a stray backslash so Traefik-style rules stay valid on the next deploy.
Multi-flag inputs (e.g. `--build-arg X=Y --link a --link b`) used to be stored as a single line, which bypassed the per-line filter that drops `--link` and similar flags for dockerfile-based builders. Each `--flag [value]` group is now stored as its own entry, and a `--process` typed after the app name is lifted into the subcommand flag instead of being stored as a docker option.
Adds a `--process` flag (repeatable) to docker-options:add/remove/clear/list and the new docker-options:list subcommand for querying a single process+phase pair. Process scoping is supported only for the deploy phase since build runs once per app and run covers ad-hoc commands and cron tasks where no Procfile process type is available. Storage moves from `$DOKKU_ROOT/$APP/DOCKER_OPTIONS_*` files to property lists under `/var/lib/dokku/config/docker-options/$APP/{processType}.{phase}`, with `_default_` as the sentinel for app-wide options. The install trigger migrates pre-existing DOCKER_OPTIONS_* files into property lists once and renames them to `.migrated`; a global marker makes re-runs strictly no-op. The legacy docker-args-{build,deploy,run} bash triggers are reimplemented in Go alongside a new docker-args-process-deploy trigger that surfaces per-process options to the scheduler. The :report command exposes one dynamic flag per configured `process.deploy` pair (e.g. `--docker-options-deploy.web`) and supports `--format json`. There is no `--global` flag; omitting `--process` keeps the historical default behaviour, since `--global` elsewhere in dokku means "across all apps". Closes#2441.