Automatically mark talk as watched

[justinallenmarsh]

#923 Introduced the ability for watched talks to be tracked. There are additional features that we would like to add here.

https://github.com/rubyevents/rubyevents/pull/923#issuecomment-3234997405

When the user reached 90% watched on the video, we would like to automatically mark it as complete.

• The user will have access to mark it as watched manually by click on the "mark as watched" button.

[justinallenmarsh]

Review Notes

• Visit a talk and navigate to 50% through the talk that you haven't watched.
• refresh
• The talk should not be marked as watched.

• Go to 90%
• refresh
• the talk should be marked as watched

Note Make sure that the talk progress is stored even if it's not marked as completed.