feat: port builder :report subcommands to golang

The bash :report implementations for the dockerfile, herokuish, lambda, nixpacks, pack, and railpack builders are replaced with a compiled golang binary that collects report keys in parallel and marshals json directly, avoiding the per-key subshell and jq forks that made the bash reports slow. The subcommands/report and root report trigger become symlinks to the compiled binary, while the non-report bash helpers each plugin still relies on are left in place.

plugins/builder-dockerfile/report.go

@@ -0,0 +1,66 @@
+package builderdockerfile
+
+import (
+	"github.com/dokku/dokku/plugins/common"
+)
+
+// ReportSingleApp is an internal function that displays the builder-dockerfile report for one or more apps
+func ReportSingleApp(appName string, format string, infoFlag string) error {
+	if appName != "--global" {
+		if err := common.VerifyAppName(appName); err != nil {
+			return err
+		}
+	}
+
+	var flags map[string]common.ReportFunc
+	if appName == "--global" {
+		flags = map[string]common.ReportFunc{
+			"--builder-dockerfile-computed-dockerfile-path": reportComputedDockerfilePath,
+			"--builder-dockerfile-global-dockerfile-path":   reportGlobalDockerfilePath,
+		}
+	} else {
+		flags = map[string]common.ReportFunc{
+			"--builder-dockerfile-computed-dockerfile-path": reportComputedDockerfilePath,
+			"--builder-dockerfile-global-dockerfile-path":   reportGlobalDockerfilePath,
+			"--builder-dockerfile-dockerfile-path":          reportDockerfilePath,
+		}
+	}
+
+	flagKeys := []string{}
+	for flagKey := range flags {
+		flagKeys = append(flagKeys, flagKey)
+	}
+
+	infoFlags := common.CollectReport(appName, infoFlag, flags)
+	return common.ReportSingleApp(common.ReportSingleAppInput{
+		ReportType:              "builder-dockerfile",
+		AppName:                 appName,
+		InfoFlag:                infoFlag,
+		InfoFlags:               infoFlags,
+		InfoFlagKeys:            flagKeys,
+		Format:                  format,
+		TrimPrefix:              true,
+		UppercaseFirstCharacter: true,
+		EmitLegacyPrefix:        false,
+	})
+}
+
+func reportDockerfilePath(appName string) string {
+	return common.PropertyGet("builder-dockerfile", appName, "dockerfile-path")
+}
+
+func reportGlobalDockerfilePath(appName string) string {
+	return common.PropertyGet("builder-dockerfile", "--global", "dockerfile-path")
+}
+
+func reportComputedDockerfilePath(appName string) string {
+	value := reportDockerfilePath(appName)
+	if value == "" {
+		value = reportGlobalDockerfilePath(appName)
+	}
+	if value == "" {
+		value = "Dockerfile"
+	}
+
+	return value
+}