refactor: migrate docker-options subcommands to go

Ports the user-facing CLI subcommands and lifecycle triggers from bash to go, mirroring the layout used by the ports plugin. The on-disk format (`DOCKER_OPTIONS_BUILD/DEPLOY/RUN` files), the `docker-args-build/deploy/run` triggers, and every exported helper consumed by other plugins are unchanged. Reserves the `--process` and `--global` flags on add, remove, and clear so usage today exits with a not-yet-implemented error and the surface is locked in ahead of the process-scoping work tracked in #2441.

plugins/docker-options/report.go

@@ -0,0 +1,50 @@
+package dockeroptions
+
+import (
+	"strings"
+
+	"github.com/dokku/dokku/plugins/common"
+)
+
+// ReportSingleApp displays the docker options report for a single app
+func ReportSingleApp(appName string, format string, infoFlag string) error {
+	if err := common.VerifyAppName(appName); err != nil {
+		return err
+	}
+
+	flags := map[string]common.ReportFunc{
+		"--docker-options-build":  reportBuildOptions,
+		"--docker-options-deploy": reportDeployOptions,
+		"--docker-options-run":    reportRunOptions,
+	}
+
+	flagKeys := []string{}
+	for flagKey := range flags {
+		flagKeys = append(flagKeys, flagKey)
+	}
+
+	trimPrefix := false
+	uppercaseFirstCharacter := true
+	infoFlags := common.CollectReport(appName, infoFlag, flags)
+	return common.ReportSingleApp("docker options", appName, infoFlag, infoFlags, flagKeys, format, trimPrefix, uppercaseFirstCharacter)
+}
+
+func reportBuildOptions(appName string) string {
+	return joinPhaseOptions(appName, "build")
+}
+
+func reportDeployOptions(appName string) string {
+	return joinPhaseOptions(appName, "deploy")
+}
+
+func reportRunOptions(appName string) string {
+	return joinPhaseOptions(appName, "run")
+}
+
+func joinPhaseOptions(appName string, phase string) string {
+	options, err := GetDockerOptionsForPhase(appName, phase)
+	if err != nil || len(options) == 0 {
+		return ""
+	}
+	return strings.Join(options, " ")
+}