By: Michael Lynch <git@mtlynch.io>
Show current media position on the detail page
Add an X of Y counter above the media viewer on /m/{id} and keep it
centered between the previous and next arrows.
This makes the current item position visible while reusing the same
sorted timeline order that drives adjacent navigation. The change also
adds an end-to-end test that covers the first, middle, and last items.
| Time to Start | Worker time | Duration | Time to finish | |
| Config | 3s | 1s | 1s | 5s |
| Eval | 5s | 34s | 34s | 39s |
| Build | 1m49s | 2m37s | 1m28s | 3m18s |
| Test | - | - | - | - |
| Deploy | - | - | - | - |
| Suite | 3s | 3m13s | 3m14s | 3m18s |