[BUG] Compose don't warn user for unsupported attributes

[glours]

Description

As mentioned in Compose Specification the runtime is in charge of warn the users about the unsupported attributes.

We should also reference all those attributes in the official documentation

Steps To Reproduce

See #13149 for example

Compose Version

N/A

Docker Environment

N/A

Anything else?

No response

[alexey-sh]

Would it be possible to get a quick rundown of the supported attributes in the meantime? (before the documentation gets updated since that could take a while)
I'd really appreciate it

[ndeloof]

@alexey-sh basically, compose supports none of the deploy attributes, which have been introduced for docker swarm

[Pnkcaht]

Hello again @ndeloof and @glours

I've opened a PR that adds a warning when unsupported Compose attributes are used
during project loading. At the moment this explicitly warns when the deploy
section is present, since it is ignored by docker compose outside of Swarm mode.

This makes the behavior more explicit and avoids silent misconfiguration when
users expect deploy options to be applied.

The warning logic is implemented in a small, dedicated warnings.go helper to
keep the behavior isolated and easy to extend in the future.

PR: #13517

Screenshot (Test)

Build and tests passing locally