Add encoding param to sync_item() and auto_run param to Syncer.__init__()

[sariyamelody]

Summary

Two small additions to support external consumers of Syncer that need finer-grained control over the sync process:

• auto_run=True on Syncer.__init__(): wraps the existing asyncio.run() and self.notify() calls in if auto_run:. Passing auto_run=False lets callers instantiate a Syncer to inspect purchases before deciding what to sync, without triggering a full sync immediately.

• encoding=None on sync_item(): uses encoding or self.media_format throughout the method instead of self.media_format directly. This allows per-item format overrides and avoids a potential race condition when concurrent threads call sync_item() with different formats.

Both changes are backwards-compatible. Default behavior is unchanged.

Tests

Two new tests in tests/test_sync_item.py:

• test_sync_item_uses_encoding_parameter -- verifies the encoding kwarg is passed through to the download URL call
• test_sync_item_falls_back_to_media_format_when_no_encoding -- verifies default behavior is preserved

[meeb]

Thanks, I'll take a look at these. They sound fine on paper. There's been a few AI-based PRs lately and the internals are now a bit of a mess so this may need to wait until I get time to manually refactor things.

[sariyamelody]

Thanks, I'll take a look at these. They sound fine on paper. There's been a few AI-based PRs lately and the internals are now a bit of a mess so this may need to wait until I get time to manually refactor things.

Super understandable - I'm in no big rush or anything, I just want to see the state of the art pushed, since god knows the world of self-hosting needs some real love - I appreciate you caring enough to be super responsive! Thank you for your time.

[meeb]

Actually this is fine, I need to re-org the args to some of the functions a little but might as well bundle this in before.