Add a `settings` flag to enable/disable `durable` checks

[kondratevdev]

Hi! Thanks for django-subatomic - it has been very useful in our project!

We’d like to request a built-in settings flag to toggle durable.

Current behavior

durable is always active once applied as a decorator.

Why this is needed

durable is an excellent strict guard for development/CI, but in production it can be too strict as always-on runtime behavior:

• it adds transaction-state checks around each decorated call;
• on failure, it raises immediately (which is correct semantically), but in production this can translate into user-facing request/job failures;

At the moment, we solve this with a local wrapper and project-level feature flag.

Proposal

Add an optional setting in the library, for example:

• SUBATOMIC_DURABLE_ENABLED (default True for backward compatibility)

Expected behavior:

• if True: keep current durable behavior unchanged;
• if False: return the original function (no durable guard checks).

This would let teams control strictness per environment without maintaining custom wrappers in every codebase.

As a follow-up: the same kind of toggle would also be very useful for transaction_required.

If this direction is approved, I can implement it and open a PR :)

[Peopl3s]

It would be very helpful!