fix(2michat-v2): align with #42 — add wpctl unity + user@1000 dep

Match the post-#42 pattern already used by 02-stage-audiodriver-2michat-v1:
call `wpctl set-volume @DEFAULT_AUDIO_SINK@ 1.0` after the amixer tune so
the PipeWire default sink lands at unity, and add `After=/Wants=user@1000.service`
+ `Environment=XDG_RUNTIME_DIR=/run/user/1000` to the unit so wpctl can
reach the user PipeWire socket.

Drop the `PCM 85%` amixer set: PipeWire drives PCM as hardware volume
passthrough, so wpctl unity immediately overwrites whatever we set PCM
to. Verified on satellite-bedroom: `amixer set PCM 50%` then
`wpctl set-volume @DEFAULT_AUDIO_SINK@ 1.0` leaves PCM at 100%.
Keeping the line made the intent misleading ("85% for headroom") while
having zero effect on the final state.

The rest of the amixer tuning stays — unlike WM8960 on v1 or the
DSP-driven lite board, the TLV320AIC3104 on the V2.0 HAT ships with
`HP DAC` at -23.5 dB and `HP` at ~89%. Those stages are downstream of
the PipeWire-managed PCM, so wpctl unity on its own still yields a
stuck-quiet card.

Author: genericJE

02-stage-audiodriver-2michat-v2/02-set-audio-volume/files/configure_audio.service

@@ -1,10 +1,11 @@
 [Unit]
 Description=PiCompose - Configure Audio volume setting (ReSpeaker 2-Mic HAT V2.0)
-After=sound.target alsa-restore.service
-Wants=sound.target alsa-restore.service
+After=user@1000.service sound.target alsa-restore.service
+Wants=user@1000.service sound.target alsa-restore.service
 
 [Service]
 Type=oneshot
+Environment=XDG_RUNTIME_DIR=/run/user/1000
 ExecStart=/usr/bin/configure_audio.sh
 RemainAfterExit=yes
 Restart=on-failure

02-stage-audiodriver-2michat-v2/02-set-audio-volume/files/configure_audio.sh

@@ -1,18 +1,19 @@
 #!/bin/bash
 set -u
 
-# TLV320AIC3104 mixer defaults on the V2.0 HAT are extremely quiet: the
-# HP DAC attenuates by -23.5 dB and the HP analog amp sits at ~89%. Without
-# tuning these three separate gain stages, end users report "silent card"
-# even with HA / LVA output at maximum.
+# TLV320AIC3104 codec defaults on the V2.0 HAT are extremely quiet: HP DAC
+# attenuates by -23.5 dB and HP / Line analog amps ship at ~89% and muted
+# on some units. Without tuning these codec-internal gain stages, end users
+# report "silent card" even with HA / LVA output at maximum.
+#
+# We deliberately do NOT set PCM here — PipeWire drives that control as
+# hardware volume passthrough, and the wpctl call below would overwrite
+# any value we set anyway. User-facing volume is the HA media_player /
+# wpctl sink level.
 #
 # Runs on every boot via configure_audio.service — PipeWire / WirePlumber
 # manages ALSA mixer state per session and can reset controls to 0% between
 # reboots, so a first-boot-only guard would let users end up stuck silent.
-#
-# Values below are the safe defaults calibrated against JST-connected
-# speakers (peaks clip at 100% PCM). Tune further in-field with `amixer`
-# and persist via `alsactl store`.
 
 wait_for_card_and_control() {
   local card="$1"
@@ -73,10 +74,6 @@ CARD="seeed2micvoicec"
 
 FAIL=0
 
-# Digital pre-DAC attenuator. 100% clips on typical speakers; 85% keeps
-# headroom while still being clearly audible.
-set_control_if_exists "$CARD" "PCM" 85%            || FAIL=1
-
 # DAC output gains (ship at -23.5 dB by default — main source of quietness).
 set_control_if_exists "$CARD" "HP DAC"   100%      || FAIL=1
 set_control_if_exists "$CARD" "Line DAC" 100%      || FAIL=1
@@ -90,4 +87,10 @@ if [ "$FAIL" -ne 0 ]; then
   exit 1
 fi
 
+# Match the project pattern (see 02-stage-audiodriver-2michat-v1 and #42):
+# keep the PipeWire default sink at unity so HA / LVA volume reaches the
+# ALSA stages we just tuned. wpctl needs the user PipeWire socket, which
+# is why this unit has After=user@1000.service and XDG_RUNTIME_DIR set.
+wpctl set-volume @DEFAULT_AUDIO_SINK@ 1.0
+
 alsactl store

docs/hardware_2mic_v2.md

@@ -33,7 +33,7 @@ Unlike v1 — which needs an out-of-tree DKMS kernel module — v2 uses the main
 2. `dtparam=i2c_arm=on` in `/boot/firmware/config.txt`.
 3. Mixer tuning on first boot — the TLV320 ships with three separate attenuators all well below 100 % (`HP DAC` at -23.5 dB in particular), producing a card that appears to work but is inaudible at typical application volumes.
 
-The PiCompose `02-stage-audiodriver-2michat-v2` stage performs all three steps automatically. The mixer tuning is applied by `configure_audio.service` on every boot: PipeWire / WirePlumber manage ALSA state per session and can reset the mixer between reboots, so a first-boot-only guard would let users end up stuck at 0%. Customization via `amixer` is still possible at runtime — it just won't survive a reboot.
+The PiCompose `02-stage-audiodriver-2michat-v2` stage performs all three steps automatically. The mixer tuning is applied by `configure_audio.service` on every boot, the same pattern other audiodriver stages follow after #42: amixer on the codec-specific controls, then `wpctl set-volume @DEFAULT_AUDIO_SINK@ 1.0` to keep the PipeWire sink at unity. PipeWire / WirePlumber manage ALSA state per session and can reset the mixer between reboots, so a first-boot-only guard would let users end up stuck at 0%. Customization via `amixer` is still possible at runtime — it just won't survive a reboot.
 
 ## Additional information