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.
The :list subcommand had `SetInterspersed(false)` which forced flags to come before positional arguments; in practice users invoke it as `docker-options:list <app> --process X --phase Y`. Drop the non-interspersed setting so flags can appear after the app name. Two existing buildpacks/dockerfile tests appended directly to the legacy `DOCKER_OPTIONS_DEPLOY` file - that path is no longer the source of truth, so switch them to `docker-options:add`. The new migration test invoked `dokku plugin:trigger install` which fans out to every plugin and trips on unrelated permission errors; call the docker-options install binary directly instead. Tighten the report and JSON assertions to match the actual output format (`.` becomes a space in the display key, and JSON values may concatenate options).
When developing Dokku, it is useful to use a real domain to test actual functionality. This is impossible if the domain is hardcoded to dokku.me in testing.
