Portal skip, pause and cancel no longer double-send on a lost response

Subscribers skipping, pausing, or cancelling a subscription in the customer portal could previously end up sending the same action twice, for example by pressing the button again, opening a second tab, or reloading mid-request; a lost response could also show an error for an action that had actually gone through.

Every money action in the portal, including skip, pause, cancel, and cancellation-flow offers, is now guarded against this: while an action is in flight, a repeat attempt on the same contract is held back rather than sent again, and if a response is lost, the portal re-reads the contract to confirm what actually happened instead of guessing from the missing response. Subscribers also no longer see an error toast for a skip the backend was always going to refuse, such as one outside the allowed skip window.

This changes only how the portal confirms and guards these actions against duplicate or lost-response scenarios; it does not change what skip, pause, or cancel themselves do to a subscription.