Waiver integrity audit: 2 stuck waiver signatures

The daily read-only waiver integrity audit found signatures the async pipeline left behind (#1203). Re-enqueue missing PDF renders and resend unsent verification emails from the signed-waivers console -- this audit never modifies signatures.

Check Signer Waiver When Problem
pdf_missing Jordan Learner <jordan@example.com> waiver 2 2026-08-23 02:06:38.035886Z completed but the signed PDF never rendered
pdf_missing Casey Trainee <casey@example.com> waiver 2 2026-08-23 02:06:38.044489Z completed but the signed PDF never rendered