Fix draft release lookup during verification

[ODevStudio]

Summary

• Fix the final draft verification failure in preview.4 preparation run https://github.com/decentespresso/openscale/actions/runs/34490807410.
• Resolve the draft's numeric database ID using gh release view, which supports drafts, then fetch the complete REST metadata by ID. GitHub's release-by-tag REST endpoint returns 404 for this unpublished draft.
• Keep tag, release ID, draft/prerelease classification, asset inventory, signature, candidate, and successful-preparation checks intact. The shared lookup fixes both preparation and publication verification.

Validation

• Added a regression test that reproduces the old HTTP 404 for stable and preview drafts; it fails before the fix and passes afterwards.
• All 16 release-publication tests passed, including fail-closed lookup checks and existing replacement/asset-change/publication failure cases.
• Release workflow contract tests and git diff --check passed.
• Read-only live check with the fixed helper successfully validated preview.4 draft ID 386379772 and its eight assets.

Release State

The preview.4 tag and failed-run draft are unchanged and unpublished. This PR does not dispatch release workflows or bypass failed preparation evidence. Merge this fix before planning the preparation retry; rerunning the old candidate unchanged would still load its old helper.