Description:
The app incorrectly indicates Fajr as the next prayer when it should show Isha for times after midnight. This occurs specifically in the following scenario:

Current time: 00:45
Isha time: 01:00 (next day)
System incorrectly shows: "Fajr in 04:14"
Expected behavior: Should show "Isha in 00:15"

Root cause:
The issue appears to be in the time comparison logic that doesn't properly handle prayer times crossing over midnight into the next day. The nextSalahIndex() method in mosque_helpers_mixins.dart needs to be updated to handle this edge case.

Suggested fix:
Modify the time comparison logic in nextSalahIndex() to:

1. Handle Isha prayers that occur after midnight
2. Compare against the correct day's prayer times when near midnight
3. Consider adding a special case for the period between midnight and Isha