Support hierarchical recipe groups for monorepo service commands

Recipe groups are currently flat. This becomes difficult to navigate in a microservice monorepo where each service can have several kinds of commands.

For example, an alert service may eventually have commands for:

• Starting the development server
• Running scheduled jobs
• Running one-time scripts
• Importing configuration
• Database maintenance
• Running service-specific tests

A flat justfile might contain recipes such as:

[group("services")]
alert-dev:
    ...

[group("services")]
alert-check-stale-telemetry:
    ...

[group("services")]
alert-import-rules:
    ...

[group("services")]
telemetry-dev:
    ...

[group("services")]
telemetry-replay-packets:
    ...

As more services and commands are added, the services group becomes a long flat list. Recipe-name prefixes provide some organization, but the relationship between the service, command type, and command is not represented in just --list.

Desired output

I would like just --list to support a hierarchy similar to:

[services]
    [alert-service]
        [development]
        dev

        [jobs]
        check-stale-telemetry

        [scripts]
        import-rules
        validate-rules

    [telemetry-service]
        [development]
        dev

        [scripts]
        replay-packets

This would make it easier to discover:

• Which commands belong to each service
• What kind of operation each command performs
• Which development, job, script, and maintenance commands are available

Possible syntax

One possible syntax could be a group path:

[group-path("services", "alert-service", "development")]
alert-dev:
    ...

[group-path("services", "alert-service", "jobs")]
alert-check-stale-telemetry:
    ...

[group-path("services", "alert-service", "scripts")]
alert-import-rules:
    ...

Another option could be a path-like group name:

[group("services/alert-service/jobs")]
alert-check-stale-telemetry:
    ...

The exact syntax is less important than representing the hierarchy in just --list.

Why existing flat groups are not enough

A recipe can be placed in multiple groups, but those groups are displayed independently. They do not represent a parent-child relationship.

For example:

[group("services")]
[group("alert-service")]
alert-dev:
    ...

This lists the same recipe under two separate flat groups instead of showing alert-service under services.

Relation to modules

Modules support nested command invocation and are useful for splitting commands into separate justfile.

This request is specifically about hierarchical organization and discovery in the recipe-list output. It would be useful when maintainers want to keep a central justfile or organize commands through metadata without requiring every service and command category to become a separate module.

If nested modules already provide the intended solution, improved documentation or an option to render all module commands as a complete tree in just --list could also address this use case.

Example use case

Consider a growing Python microservice monorepo:

services/
    alert/
    telemetry/
    command/

Each service can eventually have:

• Development server commands
• Background jobs
• Scheduled tasks
• One-time scripts
• Maintenance operations
• Service-specific tests

Hierarchical groups would make the root command list easier to understand without relying on increasingly long recipe names.