fix: close the root container after every after_shutdown hook

[lesnik512]

What changed

setup_di used to register container.close_async as an after_shutdown hook when it was called. FastStream runs after_shutdown hooks in registration order, so a hook registered after setup_di ran against a closed root and got ContainerClosedError, after the APP finalizers had already run.

With manage_lifespan=True, setup_di now registers one on_startup hook that opens the root and, on the first startup only, appends close_async to the after_shutdown hooks. By then the user has registered their hooks, so the close runs after all of them. A flag in the closure stops a restarted app from appending the close a second time. This follows the startup install of the middleware in ADR 0002.

manage_lifespan=False is unchanged: neither open nor close is registered.

FastStream details this relies on (0.7.7)

• on_startup and after_shutdown append an apply_types wrapper to the lists _on_startup_calling and _after_shutdown_calling. Because of the wrapper, a membership check on the original callable does not work, so the guard is a flag.
• start() iterates _on_startup_calling and stop() iterates _after_shutdown_calling only at shutdown, so appending to the shutdown list during startup takes effect in the same cycle. TestApp calls the same start() and stop().
• AsgiFastStream inherits both methods. as_asgi() (AsgiFastStream.from_app) shares the four hook lists with the original app, so the close lands in the right list whether setup_di gets a FastStream, an AsgiFastStream, or a FastStream that is converted later.

Limits

• A FastStream(lifespan=...) context manager exits after all hooks, so its teardown still runs after the close. FastStream has no public hook after it. The README now says so and points to manage_lifespan=False for that case.
• An after_shutdown hook appended during startup by an on_startup hook registered after setup_di runs after the close. The same goes for a hook registered between two runs of the same app, since the close keeps its position from the first startup.

Tests

test_after_shutdown_hook_registered_after_setup_di_sees_the_open_root registers an after_shutdown hook after setup_di, runs two TestApp cycles, and checks that the hook resolves the APP dependency before it is finalized, that the finalizer runs once per cycle, and that close_async is called once per cycle. It runs on a FastStream, an AsgiFastStream, and a FastStream converted with as_asgi() after setup_di. All three failed on main with ContainerClosedError. With the guard removed the close count check fails. The existing manage_lifespan=False tests still pass. The repro from the issue now prints ['user:live', 'finalized'] for every hook case.

Closes #82