Every `:report` subcommand now recognizes `--global` as a scope selector that limits the report to globally-configured properties, including in JSON form via `--global --format json`. Previously this combination was rejected because `--global` was treated as an info flag, conflicting with `--format`. The shared `common.ParseReportArgs` helper now returns a `ReportArgs` struct exposing the parsed scope; each Go and bash report selects a global-only flag map when scope is global, and skips per-app verification.
The implementation was very heavily docker-local specific and thus didn't make a ton of sense to keep in the cron plugin.
This also re-introduces changes from #5908 to parallelize the crontab generation (which is also specific to the docker-local scheduler) that were lost during a rebase.
The impetus for this change was implementing a `cron:run` command. The logic for actually running the command isn't scheduler specific - merely invoking `dokku run` with the appropriate arguments - but all the logic around how the commands were retrieved were, so the change was made pre-emptively.
This functionality enables users to manage a global crontab for the Dokku user that contains all scheduled tasks across all apps. Alternative schedulers can implement cron tasks as desired.
