Thanks @tomp for pointing me to the journalctl logs.
I was able to solve this problem - perhaps I got lucky, but in case it helps someone else, here’s what I did.
So putting together info from this post on the dqlite github page with my situation below (reconstructed, so the date/times are not the actual)
Jun 08 2023 12:34:16 root@pogo:/var/snap/lxd/common/lxd/database/global# ll
drwxr-x--- 4 root root 4096 Jun 7 22:48 ./
drwx------ 4 root root 4096 Jun 7 22:49 ../
-rw------- 1 root root 8377384 Feb 22 00:33 0000000000014337-0000000000015151
-rw------- 1 root root 1033208 Feb 22 23:17 0000000000015152-0000000000015251
-rw------- 1 root root 1169264 Feb 23 22:19 0000000000015252-0000000000015360
-rw------- 1 root root 8381408 Mar 3 17:19 0000000000015361-0000000000016173
-rw------- 1 root root 2182112 Mar 5 18:19 0000000000016174-0000000000016384
-rw------- 1 root root 8377344 Mar 13 14:19 0000000000016385-0000000000017198
-rw------- 1 root root 2149152 Mar 15 14:19 0000000000017199-0000000000017408
-rw------- 1 root root 5938944 Mar 21 01:33 0000000000017409-0000000000017985
-rw------- 1 root root 4587576 Mar 25 05:33 0000000000017986-0000000000018432
-rw------- 1 root root 8385552 Apr 2 01:33 0000000000018433-0000000000019246
-rw------- 1 root root 2149152 Apr 4 01:33 0000000000019247-0000000000019456
-rw------- 1 root root 8381560 Apr 11 21:33 0000000000019457-0000000000020272
-rw------- 1 root root 2149064 Apr 13 20:33 0000000000020273-0000000000020480
-rw------- 1 root root 5290168 Apr 18 19:13 0000000000020481-0000000000020996
-rw------- 1 root root 5228120 Apr 23 14:13 0000000000020997-0000000000021504
-rw------- 1 root root 8381448 May 1 09:14 0000000000021505-0000000000022318
-rw------- 1 root root 2165624 May 3 09:14 0000000000022319-0000000000022528
-rw------- 1 root root 8380760 May 10 23:14 0000000000022529-0000000000023332
-rw------- 1 root root 421616 Jun 7 21:40 0000000000023333-0000000000023374
-rw------- 1 root root 4184 Jun 7 21:40 0000000000023375-0000000000023375
-rw------- 1 root root 226952 Jun 7 21:40 0000000000023376-0000000000023392
-rw------- 1 root root 408608 Jun 7 21:40 0000000000023376-0000000000023407
-rw------- 1 root root 651264 May 31 12:59 db.bin
-rw------- 1 root root 32 Oct 3 2022 metadata1
-rw------- 1 root root 8388608 Jun 8 11:49 open-1
-rw------- 1 root root 8388608 Jun 7 22:48 open-2
-rw------- 1 root root 8388608 Jun 7 22:48 open-3
-rw------- 1 root root 72150 Apr 23 14:13 snapshot-1-21504-8809030973
-rw------- 1 root root 56 Apr 23 14:13 snapshot-1-21504-8809030973.meta
-rw------- 1 root root 107155 May 3 09:14 snapshot-1-22528-9655034584
-rw------- 1 root root 56 May 3 09:14 snapshot-1-22528-9655034584.meta
I started by backing up lxd.
Inferring from the dqlite github link above, I moved 0000000000023333-0000000000023374, 0000000000023375-0000000000023375, 0000000000023376-0000000000023392, and 0000000000023376-0000000000023407 into an archive directory.
Next I attempted to downgrade lxd to the snap lxd 5.0/stable channel. Once again I was thwarted, as my schema, even with the files above removed, remained at 43.
So I changed the snap lxd channel back to latest/stable and lxd happily started up.
I have put a hold on the lxd snap updates to prevent unattended/unintentional updates from breaking this production server.
I’d prefer to be on a stable channel, but I guess I’ll have to wait for 6.0.