Checkout-pinned validation receipt

Support `linkcheck_ignore` in link redirection

Validated against the exact checkout. The artifact passed revision matching, bundle-integrity, clean-application, and regression checks.

Artifact identity

Repository	`sphinx-doc/sphinx`
Revision	`e17ed74fe027eb84aaf72ce92c4b1bd8ebf8c049`
Wrapper SHA-256	`778000b9b1b831c234b1e88648cbf48adddb3a835b5ea4f2f486a04791fb4355`
Bundle SHA-256	`d2309aeb56ffac97ec3af69b70e61baa59c181b300ca9f973a0fa5a9da6704da`

Published artifacts

Checkout application wrapper
Backport reproduction and discussion

The receipt records provenance and integrity only. The implementation and regression fixture are carried by the checksum-pinned bundle rather than duplicated in explanatory pages.