Extract VM harness into standalone repo (Corer)

[obj-p]

Summary

Extract the VM harness under research/vm/ (plus the research/scripts/ research directions) into a new standalone repository called Corer ("like an apple corer"). This is a tracking issue only. No implementation is planned here.

The VM kit is a general-purpose headless macOS-VM-on-Apple-Silicon driver (boot / ssh / stop / install / snapshot). It has zero PreviewsMCP-specific shape and was always designed to be separable. See project-vm-kit-extractable memory (direction set by Jason 2026-05-17) and the "Big design decisions" section of research/vm/PROGRESS.md.

Why a separate repo

• The wrapper's automation surface has no PreviewsMCP coupling. It is a general macOS-VM library.
• Licensing void in this space is what made the custom wrapper necessary: Tart is Fair Source, UTM is GPL-3.0, macosvm is minimally maintained.
• Keeping it in PreviewsMCP mixes a general tool with product-specific research.

Decisions (agreed)

• Extraction method: clean snapshot. No git history carried over.
• Scope: VM Kit plus the research/scripts/ research directions as subdirectories. Personal use only; not intended for external consumers. (Note: this is broader than the original memory, which framed extraction as the VM kit alone.)
• Layout: research directions live as subdirectories (Xcode Previews today, future ones later).
• Naming: library renamed to CorerKit or CorerVM (final pick TBD). CLI currently previewsvm.

Source branch

Snapshot from previews-research-3201, not previews-research. The -3201 branch is 437 lines ahead in research/vm/Sources/previewsvm/SetupCommand.swift.

What gets extracted

research/vm/ — self-contained Swift package PreviewsVM:

• Library PreviewsVMKit (+ ObjC shim PreviewsVMObjC linking Virtualization)
• CLI previewsvm (subcommands: boot, install, ssh, setup, snapshot, status, stop, plus test-keys / test-vnc smoke tests)
• Only external dependency: swift-argument-parser
• Intentionally not a target of the root Package.swift

research/scripts/ — research directions and analysis (Xcode Previews investigation: w3-w7 analysis, jit runtime findings, data captures, etc.).

research/scripts/provision-and-capture.sh and research/vm/build.sh — supporting scripts.

Design rule to preserve (from memory)

Keep PreviewsMCP-specific assumptions out. No references to the main Sources/ modules, no hard-coded Xcode-Previews internals, no coupling to the root Package.swift. Provisioning hooks (SIP disable, AMFI off, Xcode install) should stay parameterized / pluggable, not hardcoded. Extend the per-bundle config.json pattern instead of a repo-wide config.

References

• Memory: project-vm-kit-extractable (direction set 2026-05-17)
• Memory: project-vm-setup-assistant-via-snapshot, project-vm-sa-complete-macos-26-3-1 (SA sequence + provisioning findings)
• research/vm/PROGRESS.md — "Big design decisions" section
• research/vm/README.md — why the package is separate from root
• prompts/jit-executor-research.md — original W1 harness brief