gig: the UMC came up input-only, and that is why nothing reached it

On stage, 15:05. The interface enumerated fine — USB bus, ALSA card 3 — and
the graph still had no trace of it, because PipeWire had it on the
input:analog-stereo profile: zero sinks, microphone ports only. Presence
was never the question.

pro-audio is the only profile on this device that carries a sink at all, so
there was no choice to make. Switched, and Master linked to it by hand;
check-audio-graph now passes its own monitor-path test and reports the
interface clocking at realtime across three samples.

Master still feeds the laptop too, deliberately, until the PA is confirmed
audible. Both the cut command and the durable Ardour-side fix are on the
card, because hand-made links do not survive a restart.

TODO_GIG.md

@@ -12,33 +12,41 @@
 
 # DO THIS, IN THIS ORDER
 
-- [ ] **1. Bluetooth off.**
+- [x] **1. Bluetooth off.** DONE — checked, `Powered: no`.
 
-      bluetoothctl power off
+- [x] **2. UMC plugged in.** DONE — USB bus, ALSA card 3.
 
-      Why: a phone reconnecting restarts the audio system. That kills every
-      cable in the graph, mid-set. Venue = 200 phones.
+- [x] **3. UMC wired to Ardour.** DONE at 15:05, and it was broken exactly the
+      way we predicted. The box had come up **input-only** (profile
+      `input:analog-stereo`, zero outputs), so nothing could ever reach it.
+      Switched to `pro-audio` and linked Master to it by hand.
 
-- [ ] **2. Plug the UMC box in BEFORE you open Ardour.**
+      If it ever goes quiet again, this is the whole fix:
 
-      Why: Ardour reloads the ports it saved last time. It does NOT follow
-      whatever you plugged in after. Plugged in ≠ being used.
+          pactl set-card-profile alsa_card.usb-BEHRINGER_UMC202HD_192k_12345678-00 pro-audio
+          pw-link "ardour:Master/audio_out 1" alsa_output.usb-BEHRINGER_UMC202HD_192k_12345678-00.pro-output-0:playback_AUX0
+          pw-link "ardour:Master/audio_out 2" alsa_output.usb-BEHRINGER_UMC202HD_192k_12345678-00.pro-output-0:playback_AUX1
 
-- [ ] **3. Check the sound actually goes to the UMC.**
+- [ ] **4. Can you HEAR the UMC? Say so, then cut the laptop speakers.**
 
-      tools/check-audio-graph.sh
-      pw-link -l | grep -A3 'ardour:Master'
+      Right now Master goes to the UMC **and** the laptop, on purpose, so you
+      always have something. Once the PA is confirmed, cut the laptop — on
+      stage its speakers are just a feedback path:
+
+          pw-link -d "ardour:Master/audio_out 1" alsa_output.pci-0000_00_1f.3-platform-sof_sdw.HiFi__hw_sofsoundwire__sink:playback_FL
+          pw-link -d "ardour:Master/audio_out 2" alsa_output.pci-0000_00_1f.3-platform-sof_sdw.HiFi__hw_sofsoundwire__sink:playback_FR
+
+- [ ] **5. Re-point Master inside Ardour, then Ctrl+S.**
 
-      You want to see the UMC in there. If you see `sof_sdw` or `pci`,
-      that's the laptop speakers — re-point Master in Ardour.
+      My links work NOW but they are hand-made. Ardour reloads its own saved
+      ports, so after any restart it goes back to the laptop. Fix it for real
+      in Ardour (Window > Audio Connections), then save.
 
-- [ ] **4. Master fader up with the mouse. Then Ctrl+S.**
+- [ ] **6. Master fader up with the mouse. Then Ctrl+S.**
 
-      Master has no knob on the LCXL3, so it's mouse-only. Save while the
-      faders are where you actually play. That save is the only way any
-      tool can check the mix later.
+      Mouse-only, no knob for it. Save while the faders are where you play.
 
-- [ ] **5. Play.**
+- [ ] **7. Play.**
 
 ---