Trial tenant improvements and AI-assisted action creation

Trial period countdown banner. Tenants on a trial now see a persistent banner counting down the time remaining, so it's always clear how much of the trial is left.

Auto-titling and mapping from the action view. Creating an action now uses AI to draft a title and propose control mappings on the fly, letting admins fill in intent with a short prompt instead of typing a fully-formed action from scratch.

Framework export includes artifacts, available on trial. Framework exports now include the associated evidence artifacts alongside controls, actions, and configured metadata, giving admins and auditors a complete, portable snapshot of a framework's state. This full export is now available to trial tenants as well, matching the export flow on paid plans.