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.
The docker-options DOCKER_OPTIONS_<PHASE>.migrated sentinels and the storage data/storage-registry/migrations/<app> flag files are now stored as per-app properties (`migrated-<phase>` and `legacy-mounts-migrated` respectively), so they survive a property-store backup/restore and align with the existing `migrated-from-files`, `env-migrated`, and `nginx-conf-sigil-migrated` patterns. The new markers are written only when a non-empty legacy source was actually migrated, distinguishing apps that never had legacy state from apps that did and were drained. A one-cycle upgrade-cycle conversion drains any leftover filesystem sentinels into the new properties and removes the files; for docker-options the conversion deliberately runs before the global `migrated-from-files` short-circuit so installs upgrading from the previous release still get their `.migrated` files converted.
The bats test for migration idempotency invoked the install binary directly via sudo, which kept hitting fresh missing env vars on each iteration (DOKKU_LIB_ROOT, then PLUGIN_PATH, etc). The dokku launcher script exports a chain of vars that the install path reads via common.MustGetEnv, and mirroring that chain in a bats test is fragile. Migration is pure file IO plus a property marker - perfect for a Go unit test that isolates itself with t.TempDir and t.Setenv. The new test covers parsing comments and blank lines, the marker-based no-op on re-run, and the rule that a manually re-created legacy file is left untouched after the marker is set.
