Closing ceremony script should warn loudly if event is not completed yet before advancements section

**Is your feature request related to a problem? Please describe.**
Currently, the closing ceremony script shows the advancement with team numbers and names, even if the event hasn't fully concluded yet (even just after setup when no matches have been played! though in reality, we ran into this when we loaded the script during the first playoff break and then read off the wrong list of names during the end of the event -- luckily, we quickly realized why it was different than the displays and got the emcee to refresh and reannounce).

**Describe the solution you'd like**
The advancements report has a red warning banner at the top. The same warning banner should appear in the closing ceremony script in the Advancement section.

**Describe alternatives you've considered**
Remember to ask the emcee to refresh the page at the end.
Refresh the page automatically via a websocket call or equivalent update.

**Additional context**
This is the closing ceremony script output, even before any matches were generated:

Start with the closing ceremony script output and compare its Advancement section with the advancements report, which already shows the requested red warning banner. The work is done when the same warning appears before advancement details whenever the event has not fully concluded, including before any matches are played.

Written by the indexing model from the issue text.