Trust: spine-cover IntlDateFormatter formatObject units after #20825/#20819 (#10533)

[PurHur]

Summary

• After Stdlib: IntlDateFormatter::formatObject / datefmt_format_object (#20813) #20825 / Stdlib: IntlDatePatternGenerator create/getBestPattern (#20740) #20819 landed IntlDateFormatterFormatObject, datefmt_format_object, and VmIntlDatePatternGenerator in inventory, spine coverage drifted (3 missing requires), turning Pillar 1 red (user_release_ready: no, north-star5-fast fail).
• Append spine require_once for the three units, rewrite footnotes/assertion to 5853/5853, and refresh gen-0 sidecar stamp (stamp-only).

Refs #10533 (Pillar 1 trust). Same shape as #20550 / #20759.

Lane A note: no eligible implementation-ready language issue this run (queue is stdlib/ext/php-in-php/meta/CI); fixing Trust P0 instead.

Test plan

• php script/check-selfhost-spine-coverage-sync.php → OK (spine covers all 5853 inventory files)
• php script/check-selfhost-spine-sidecar-sync.php → OK (cb24556d…)
• make north-star5-verify-fast → OK (fast)
• ./script/release-readiness.sh --json → user_release_ready: yes (5/5 quick)

Verification transcript

check-selfhost-spine-coverage-sync: OK (spine covers all 5853 inventory files)
check-selfhost-spine-sidecar-sync: OK (stamp matches spine entry SHA-1 cb24556d753ebef497aa2a81de8be3c2e8da0acc)
bootstrap-spine-count: 5853/5853

north-star5-verify: OK (fast — use --strict before merging bootstrap/M5 work)
Spine: 5853/5853

release-readiness --json:
  user_release_ready: yes
  bootstrap-inventory: ok (OK 5853/5853)
  spine-coverage: ok
  root-readme-sync: ok
  north-star5-fast: ok
  vm-driver-probe: ok

Made with Cursor