feat(B-0590): decompose slice 1 (KVM hardware evaluation)

[AceHack]

Summary

Peeling off Slice 1 from PR #3986 blob for detailed hardware evaluation and pilot gating.

Scope: stub/scaffold only. This PR creates the eval-doc skeleton at docs/research/2026-05-17-kvm-eval.md (currently just a top-level heading). Detailed hardware evaluation and pilot-gating content lands in follow-up slice PRs against the same file — keeping per-slice diff small and reviewable per decompose-to-dissolve-ambiguity discipline (PR #2999).

Per B-0590 slice 1 decomposition: parent PR #3986 carries the umbrella row; this slice opens the eval surface so subsequent slices have a target file to extend.

Test plan

• file path matches B-0590 slice 1 expectation
• follow-up slices have a target file to extend
• CI gate green (in-progress)

[Copilot]

Pull request overview

Adds a new research document intended to capture Slice 1 of B-0590 (KVM hardware evaluation) as a standalone artifact for subsequent evaluation/gating work.

Changes:

• Introduces a new docs/research/2026-05-17-kvm-eval.md document.
• Seeds the document with an initial top-level heading.

[AceHack]

Substrate-honest read: thread accurate. Resolving via title/body clarification rather than premature content because the parent decomposition pattern (B-0590 slice 1 from PR #3986) puts evaluation content in subsequent slices targeting the same file. PR description now names "stub/scaffold only" explicitly. Detailed hardware evaluation lands in follow-up slice PRs.