Expose a way to manage downloaded models

[ashtonmeuser]

It seems as though once downloaded, models can take up space with no simple way to find and delete them. Seeing as models are typically quite large, it would be great to expose a model management system. LocalLLMClient's FileDownloader exposes the final destination of the downloaded model, so we could keep track of this ourselves, but this may be a common pain point for users.

See MlxModelManager in the https://github.com/mi12labs/SwiftAI project.

[tattn]

This library still lacks some interfaces needed for building apps, so I plan to add them gradually while considering their necessity.

I also think the issue of difficulty accessing the model path when using LLMSession is something that should be resolved quickly, so I decided to add a modelPath property to DownloadModel.
#66

With this, users will be able to manage models more freely using the standard FileManager.
Please try it out on the latest main branch.

As for whether to provide a utility class like ModelFileManager, I will consider it while taking into account maintainability, flexibility, and demand.

[james-333i]

@ashtonmeuser I did something like this in my own custom code:

@objc public func deleteCoreModel(_ model: IVAIModel) throws {
    let modelID = model.modelID
    guard !modelID.isEmpty else { return }
    print("AIManager - Deleting Model: \(model.modelID)")
    let globs = Globs([model.modelFilename].compactMap { $0 })
    let source = FileDownloader.Source.huggingFace(id: modelID, globs: globs)
    let downloader = FileDownloader(source: source)
    
    // Remove metadata
    try downloader.removeMetadata()
    
    // Remove folder
    let fileManager = FileManager.default
    if fileManager.fileExists(atPath: downloader.destination.path) {
        try fileManager.removeItem(at: downloader.destination)
    }
    let providerFolder = downloader.destination.deletingLastPathComponent()
    if let contents = try? fileManager.contentsOfDirectory(atPath: providerFolder.path),
       contents.isEmpty {
        try fileManager.removeItem(at: providerFolder)
    }
}

Whatever object you have stored somewhere would just keep to keep the modelID which would be something like:
mlx-community/Phi-4-mini-instruct-4bit

[ashtonmeuser]

I ended up with this. I would like to maintain a single canonical model e.g. Qwen2.5 1.5B. If I change the model in the future, I'd like to remove all previously downloaded models.

[tattn]

@ashtonmeuser Thank you for the PR!
I understand your needs — you’d like to have an API that makes it easy to delete models even when the app doesn’t keep information about old models.

Such an API could be a good fit for this library.
I’ll review the PR and leave comments.