Accidentally ran partitionDisk command on disk1
Your real (physical) disk is your SSD/disk0. Disk1 is a virtual ("synthesized") disk based on the APFS physical store disk0s2.

Disk1 doesn't have a partition scheme. Additionally it contains your boot volume disk1s1.

Therefore the command diskutil partitionDisk ... run booted from your main boot volume (Macintosh HD) shouldn't be able to completely repartition and reformat neither disk0 nor disk1.

You can verify the disk and the APFS container/volumes with:

diskutil verifyDisk disk0 # verify physical disk
diskutil verifyVolume disk0s2 # verify APFS container
diskutil verifyVolume disk1s1 # verify APFS boot volume


The second command may yield something like:

warning: Overallocation Detected on Main device: (626695+1) bitmap address (28278)


which seems to be normal.

The third command usually checks all available APFS volumes despite passing on only one slice (disk1s1).

Therefore you will/should see the output:

Checking the APFS volume superblock
Checking the object map
Checking the fsroot tree
Checking the snapshot metadata tree
Checking the extent ref tree
Checking the snapshots


several times.

"The partition map appears to be OK" or "exit code is 0" indicates that everything is OK.