post https://api.flextract.dev/api/folders//merge/to//
Merge one folder into another by moving all files from the source folder to the destination folder.
This operation:
1. Moves all files from the source folder to the destination folder
2. Re-runs checklist matching for all moved files
3. Runs flow hydrations for all moved files
4. Archives (deletes) the source folder
Both folders must be accessible to the authenticated user.
