failManageAction error helper not adopted outside manage-actions.ts
Imported from GitHub issue El-SaMa/oma#106 by @El-SaMa.
`apps/web/lib/enhance/manage-action-errors.ts` (`failManageAction`, `ManageActionResult`) is only imported by 6 files (the client `services/[id]/-actions.ts` files). 15+ other server-action files (cloudflare/actions.ts, cpanel/actions.ts, and most admin/integrations//actions.ts) use ad-hoc try/catch with inconsistent error shapes.
Fix: adopt `failManageAction`/`ManageActionResult` as the standard return shape for all mutating server actions; refactor the worst offenders (cloudflare/actions.ts, cpanel/actions.ts) first.