Refactor: Remove driver.BaseDriver, move drivers and image-downloader to pkg/driver

[unsuman]

This pull request introduces a significant architectural refactoring to the driver implementation in Lima. It is the foundational first part of the larger GSoC project and prepares the codebase for upcoming features by improving modularity and support for external drivers. This PR sets the project structure and refactoring needed for the next three submissions.

Key Changes

• Removal of driver.BaseDriver: The BaseDriver struct has been removed. Interface functions are implemented directly within the specific drivers.
• Project Restructuring: All driver-specific packages have been consolidated under pkg/driver/ directory. This co-locates driver code (e.g., pkg/qemu is now pkg/driver/qemu).
• Image Downloader: The image downloader logic has been moved into the main Lima program to make it a shared utility.

GSoC Context

This is the 1st of 4 PRs that make up my initial GSoC project submission for mid-term evaluations. Merging this foundational PR is a prerequisite for the subsequent three, which will build upon this new architecture.

Related Issues

• Closes Consolidate pkg/{qemu,vz,wsl2} to pkg/driver #3499
• Closes Remove BaseDriver struct #3567

[alexandear]

Please fix lint issues.

[afbjorklund]

Why do we still need sshLocalPort as a parameter, and not just instance? Is that for the obsolete 60022

Eventually I wanted to refactor it into host and port (and not hardcode localhost), but that's a separate topic

[AkihiroSuda]

Thanks, I'm merging this.

The comment about the ssh port can be addressed separately

[norio-nomura]

This PR disables kernel decompression for vz instances.
before:

lima/pkg/vz/disk.go

Line 45 in b94e2fc

if _, err := fileutils.DownloadFile(ctx, kernel, f.Kernel.File, true, "the kernel", *driver.Instance.Config.Arch); err != nil {

after:

lima/pkg/instance/start.go

Line 120 in d32847c

if _, err := fileutils.DownloadFile(ctx, kernel, f.Kernel.File, false, "the kernel", *inst.Config.Arch); err != nil {

Since vz doesn’t support compressed kernels, booting with one causes the VM to fail with an internal error:

{"level":"fatal","msg":"Error Domain=VZErrorDomain Code=1 Description="Internal Virtualization error. The virtual machine failed to start." UserInfo={\n NSLocalizedFailure = "Internal Virtualization error.";\n NSLocalizedFailureReason = "The virtual machine failed to start.";\n}","time":"2025-07-09T09:48:08+09:00"}