docs(qa): platform-core checklist — webhook scope wall, ui/ pin paths (#25845)

activation-ledger-row-contract (rev 8): the catalog door admits
position, permission, sharing_rule and webhook; the item now names the
webhook writer, counts six values, and reads a missing webhook row as
the declaration's own isActive.

boot-health (rev 11) and url-overlay-contract (rev 3): drop the retired
objectui-repo-only assertions; the pins are in this checkout under ui/.

Claude-Session: https://claude.ai/code/session_01VoWrGZipReMqGbFdsvCLsX
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude