The Oban queues PhoenixKit and its modules need, declared where the work is defined rather than hand-copied into a host's config.

Why

Oban only runs jobs from queues the node lists. A job inserted into a queue nothing runs sits available forever, and the feature looks fine until someone counts the rows. Until now the list lived in two places in core — the installer's block and the updater's backfill — which had already drifted (the updater wrote shop_imports: 2 while the module's own docs asked for 5), and a module had no way to declare a queue at all, so its install docs told the host to edit config.exs by hand and its workers ended up sharing default.

How it fits together

• A module declares its queues with the optional oban_queues/0 callback of PhoenixKit.Module. Core declares its own here (core_queues/0), so there is one mechanism, not a module mechanism beside a hardcoded list.
• mix phoenix_kit.install writes every declared queue into a new Oban block; mix phoenix_kit.update adds the ones an existing block is missing. Neither ever changes a limit the host already has — a number is the module author's suggestion until it lands in config.exs, and the host's from then on. A node that runs no queues (queues: false or []) is left alone.
• mix phoenix_kit.doctor reports declared queues the running config is missing, and modules that declare one queue with different limits. The application logs the same at boot, once.

Queues are per node: a limit is how many jobs of that queue one node runs at a time. Split work by what it is — interactive work a person is waiting for, batch work nobody watches — rather than one queue per package, so a 400-item import cannot hold up an image someone just asked for.

Declaring

@impl PhoenixKit.Module
def oban_queues do
  [
    image_generation: [limit: 3, kind: :interactive],
    catalogue_import: 2
  ]
end

A bare integer is the limit. :kind (:interactive or :batch) is advisory — it explains the number in the doctor's output and the generated config, and changes nothing at runtime.