When merging duplicate feeds with redirects, Follow relationships
can generate UNIQUE constraint errors if the relationship already
exists between the same profiles.
This fix:
- Iterates Follow relationships individually
- Checks for existing relationships before updating
- Deletes duplicates safely
- Adds comprehensive error handling
Similar approach to PollVote fix.
Resolves issue with feeds like haiverin.scot redirect.
Signed-off-by: Andros Fenollosa <hi@andros.dev>
75460aa567