Schedule survey popups as campaigns with start and end dates

Description: Allow administrators to define a validity period (start date and end date) for the popups linked to a survey, so that popups can be scheduled and run as a campaign. Today, several popups can be created for the same survey. This remains useful, but each popup is active until it is manually changed. With this evolution, each popup (or group of popups) would be set up as a campaign with: a start date and an end date, automatic activation and deactivation, with no manual action needed on the day, the ability to schedule several campaigns in advance for the same survey. Problem: There is currently no way to set a time frame for the popups of a survey. Users can create several popups for one survey, but they cannot run them as a campaign between two dates or schedule them ahead of time. They must activate and deactivate each popup manually at the right moment, which is time-consuming and error-prone. It is also hard to compare two periods of the same survey, because responses cannot be cleanly attributed to a given campaign or time window. Benefit: Time savings and reliability: campaigns are scheduled once and run automatically, with no manual activation or deactivation and less risk of forgetting or mistiming a popup. Better planning: survey campaigns can be prepared in advance and aligned with key moments (end of a release, a training session, a seasonal period). Period comparison: results from two distinct periods (for example before and after a change) can be compared easily, which supports measurement and decision-making. More structured survey management: several campaigns can run over time on the same survey while keeping a clear history.