fix: Retry published CLI registry lookup

[kof]

What changed

• Retry npm version and integrity resolution inside the CLI registry smoke test.
• Keep retry timing injectable so the propagation race is covered by a fast unit test.
• Preserve the final npm error when all registry attempts are exhausted.

Why

CLI 0.286.0 was published successfully, but npm briefly exposed integrity metadata while the exact version lookup still returned 404. The post-publish smoke failed and the dependent docs publication job was skipped.

The 0.286.0 documentation snapshot has been recovered directly on the docs branch.

Ref #6007

Verification

• Regression test demonstrated failing before the implementation and passing afterward
• CLI registry/versioning tests: 3 passed
• CLI typecheck
• Formatting and diff checks
• Documentation impact reviewed: no product-doc source change is needed in this PR; the missed 0.286.0 snapshot was published separately to docs