chore: refresh v2 compat goldens

[github-actions]

Weekly (or on-demand) refresh of the pinned v2 compat probes.

Pinned v2 SHA:accd6127cb78bee3e8082180cb391013d204ef9f
Captured at:2026-04-24 UTC

Drift summary

Review git diff on test/compat/testdata/golden/v2/ to see
which fixture(s) shifted and which JSON paths moved.

How to decide

• Allowlist already tolerates the drift — safe to merge;
  PR-time compat-diff would not have flagged it. Merging just
  keeps goldens close to live v2.
• Allowlist does NOT tolerate the drift — merging this PR
  makes the new v2 behavior the PR-time baseline. Open a
  separate PR to either (a) match the new v2 behavior in our
  action or (b) extend the allowlist in docs/compat-matrix.md
  with a reason:.

Opened by .github/workflows/compat-golden-refresh.yml.

[phramz]

Goldens fast-forward-merged into feat/pr-gated-v2-compat; closing the rolling drift PR.