Skaram/detect softnpu review

[sion42x]

Series of smallish commits to address @jgallagher's comments on #11237

Tested on voxel (with and without SP/RoT emu) and will be tested on a racklette after CI.

[sion42x]

@jmpesp tagging you here primarily for 4f181ec which walks back some of the symmetry in detection. Still one function for startup detection though, so hopefully this works? The change was made based on @jgallagher's comment here: #11237 (comment)

[sion42x]

I merged main in due to the CI issues and the time this PR and its parent have been open.

Tests ran successfully on voxel and omicron-simulated, exercising both SoftNPU paths. Specifically, standalone used kind = "standalone" and came online, pumpkind was skipped, the 9p probe never ran, and the scrimlet resolved. Good to see the new pathing in action there. I'll test on a racklette as well to exercise the prod path one more time while waiting for review.

[sion42x]

@jgallagher Tested on dublin, came up exactly as expected:

[dublin]root@oxz_switch0:~# pilot host exec -c 'svcs -H -o state oxide/sled-agent pumpkind; grep -c "kind = .production" /opt/oxide/sled-agent/pkg/config.toml' 14-17
14  2F8JEXDK           ok: online
online
1
15  BRM27230037        ok: online
online
1
16  BRM23230018        ok: online
online
1
17  BRM23230010        ok: online
online
1
[dublin]root@oxz_switch0:~# pilot host exec -c 'grep -c "probing virtio 9p" /var/svc/log/oxide-sled-agent:default.log; grep -h -E "Failed to detect|SledModeConfig|unknown field|pumpkind manifest" /var/svc/log/oxide-sled-agent:default.log | cut -c1-140' 14-17
14  2F8JEXDK           ok: 0
15  BRM27230037        ok: 0
16  BRM23230018        ok: 0
17  BRM23230010        ok: 0
[dublin]root@oxz_switch0:~# pilot host exec -c 'grep -h -E "Found tofino node|Updated tofino|tofino device found" /var/svc/log/oxide-sled-agent:default.log /var/svc/log/oxide-tofino-monitor:default.log 2>/dev/null | cut -c1-120 | head -2; zoneadm list | grep -c oxz_switch' 14-17
14  2F8JEXDK           ok: {"msg":"Updated tofino","v":0,"name":"SledAgent","level":30,"time":"1986-12-28T00:00:49.448956867Z","hostname":"2F8JEXDK
Dec 28 00:00:49.531 INFO tofino device found, unit: tofino-monitor
1
15  BRM27230037        failure: exit code 1: 0
16  BRM23230018        ok: {"msg":"Updated tofino","v":0,"name":"SledAgent","level":30,"time":"1986-12-28T00:00:45.47954221Z","hostname":"BRM232300
Dec 28 00:00:45.531 INFO tofino device found, unit: tofino-monitor
1
17  BRM23230010        failure: exit code 1: 0
Error: some operations failed
[dublin]root@oxz_switch0:~# 
[dublin]root@oxz_switch0:~# 
[dublin]root@oxz_switch0:~# 
[dublin]root@oxz_switch0:~# svcs -H -o state dendrite; svcprop -p config/board_rev dendrite; ls -l /dev/tofino/1
online
b
crw-------   1 root     sys      143,  1 Dec 28  1986 /dev/tofino/1
[dublin]root@oxz_switch0:~# exit
logout
stevekaram@castle ~/2bc84e9346c70f9f7d0b4553e8858380b56705b8 $ pilot tp login 1  
The illumos Project     helios-3.0.24263        September 2026
[dublin]root@oxz_switch1:~# [dublin]root@oxz_switch0:~# svcs -H -o state dendrite; svcprop -p config/board_rev dendrite; ls -l /dev/tofino/1
online
b
crw-------   1 root     sys      143,  1 Dec 28  1986 /dev/tofino/1
-bash: [dublin]root@oxz_switch0:~#: command not found
b
crw-------   1 root     sys      143,  1 Dec 28  1986 /dev/tofino/1
-bash: online: command not found
-bash: b: command not found
-bash: crw-------: command not found
[dublin]root@oxz_switch1:~# svcs -H -o state dendrite; svcprop -p config/board_rev dendrite; ls -l /dev/tofino/1
online
b
crw-------   1 root     sys      143,  1 Dec 28  1986 /dev/tofino/1

So the gist path worked, and no startup probe had to happen. Good stuff!