fix(rig): the two reconcilers that lived only in $HOME — five orbits reached no Ardour track

tidal-ardour-autoroute.service was disabled+inactive after launch: orbits 5-9
(SuperCollider:out_9..18) had NO link to their "Tidal 05..09" tracks, while
1-4 and 10-12 survived as leftovers from an earlier session. Enabled it; all
24 outs reconcile every 2s again.

Root cause of the regression is that both reconcilers — this one and
midi-autoconnect — existed ONLY as plain files in ~/.local/bin and
~/.config/systemd/user, unlike every other unit here which symlinks into
tools/. Nothing was version-controlled, so a `disable` (or a fresh systemd
user config) was unrecoverable and invisible to git. Now in the repo, with
$HOME pointing back at it. Also started parvagues-sc-watchdog, which was
linked but dead.

tools/midi-autoconnect.service

+[Unit]
+Description=Enforce fixed ALSA-seq MIDI wiring (Launch Control XL <-> Midi Through -> aseqdump)
+# Run alongside the sound/PipeWire session.
+After=pipewire.service
+Wants=pipewire.service
+
+[Service]
+Type=simple
+ExecStart=%h/.local/bin/midi-autoconnect.sh
+Restart=always
+RestartSec=2
+# Tiny footprint; it's mostly sleeping.
+Nice=10
+
+[Install]
+WantedBy=default.target

tools/midi-autoconnect.sh

+#!/usr/bin/env bash
+# midi-autoconnect — enforce a fixed ALSA-seq MIDI wiring.
+#
+# Rules (re-applied every $INTERVAL seconds, idempotent):
+#   1. Launch Control XL :0  ->  Midi Through :0   (controls out)
+#   2. ACTIVELY CUT  Midi Through :0 -> Launch Control XL :0
+#
+# aconnect matches clients by name, so this survives replug / renumbering.
+# "Connection is already subscribed" errors are expected and ignored.
+#
+# ---------------------------------------------------------------------------
+# 2026-07-27 — why rule 2 INVERTED from "connect" to "disconnect".
+#
+# The old rule 2 connected Midi Through BACK to the LCXL, labelled "LED/visual
+# feedback". It is in fact a MIDI FEEDBACK LOOP and the direct cause of the
+# long-standing "my button colours snap to yellow the moment I press them" bug:
+#
+#   press button -> LCXL emits Note On velocity 127
+#                -> LCXL:0 -> Midi Through:0 -> (rule 2) -> LCXL:0
+#                -> the LCXL reads an INBOUND note velocity as an LED COLOUR
+#                -> 127 = 0x7F = full red + full green = YELLOW
+#
+# So every press repainted itself yellow, wiping whatever the HUD had set.
+# `aconnect -d 14:0 24:0` fixed it by hand — and then this service silently
+# recreated the loop within 2 seconds, which is why the fix "never stuck"
+# across a Tidal reboot. The reconcile loop was fighting the operator.
+#
+# The LCXL's LEDs do NOT need this link: the HUD drives them directly with
+# SysEx via `aseqsend` to the LCXL's own port (lib/lcxl-leds.js). Nothing was
+# ever gained by the return leg. LCXL -> Midi Through -> Ardour still works, so
+# Ardour's click-to-map fader learn is unaffected; Ardour simply stops talking
+# back to the surface, which is what we want when the HUD owns the LEDs.
+#
+# We DISCONNECT rather than merely "not connect", because Ardour's control
+# surface and SuperCollider's `MIDIIn.connectAll` can both recreate the return
+# leg on their own. Same shape as every other binding on this rig: a
+# connection that must be re-asserted, never assumed.
+#
+# The old rule 3 (Midi Through -> every aseqdump) is gone too: aseqdump
+# clients already subscribe to the LCXL directly, so the extra hop delivered
+# every CC TWICE to the HUD — pure duplicated work on a renderer we are
+# actively trying to keep off the audio thread's back.
+# ---------------------------------------------------------------------------
+
+set -u
+
+LCXL="Launch Control XL"
+THRU="Midi Through"
+LCXL_PORT=0          # "first channel"
+THRU_PORT=0
+INTERVAL="${MIDI_AUTOCONNECT_INTERVAL:-2}"
+
+connect() {  # $1 = source, $2 = dest ; silent unless it's a real failure
+    aconnect "$1" "$2" 2>/dev/null
+}
+
+disconnect() {  # $1 = source, $2 = dest ; silent when there was nothing to cut
+    aconnect -d "$1" "$2" 2>/dev/null
+}
+
+reconcile() {
+    connect    "$LCXL:$LCXL_PORT" "$THRU:$THRU_PORT"   # rule 1: controls out
+    disconnect "$THRU:$THRU_PORT" "$LCXL:$LCXL_PORT"   # rule 2: kill the loop
+}
+
+echo "midi-autoconnect: reconciling every ${INTERVAL}s"
+while :; do
+    reconcile
+    sleep "$INTERVAL"
+done

tools/tidal-ardour-autoroute.service

+[Unit]
+Description=Auto-route SuperDirt orbits to Ardour Tidal tracks; keep SC off hardware
+After=pipewire.service
+Wants=pipewire.service
+
+[Service]
+Type=simple
+ExecStart=%h/.local/bin/tidal-ardour-autoroute.sh
+Restart=always
+RestartSec=2
+Nice=10
+
+[Install]
+WantedBy=default.target

tools/tidal-ardour-autoroute.sh

+#!/usr/bin/env bash
+# tidal-ardour-autoroute — keep SuperDirt orbits wired to their Ardour tracks.
+#
+# SuperDirt emits stereo orbit pairs on SuperCollider:out_N. Orbit k (1-based)
+# is the pair (out_{2k-1}, out_{2k}). Ardour has stereo tracks "Tidal NN".
+#
+# Rules (re-applied every $INTERVAL s, idempotent):
+#   ADD:   SuperCollider:out_{2k-1} -> ardour:Tidal {NN}/audio_in 1
+#          SuperCollider:out_{2k}   -> ardour:Tidal {NN}/audio_in 2
+#   PRUNE: drop every SuperCollider:out_* -> <hardware>:playback_* link.
+#          In this multichannel setup SC never feeds hardware directly —
+#          monitoring is via Ardour Master. sclang/SuperDirt re-adds the
+#          orbit-0 monitor (out_1/out_2 -> Headphones) on (re)boot; this kills it.
+#
+# Track numbers are auto-detected from the live graph, so adding/removing
+# "Tidal NN" tracks in Ardour needs no edit here. pw-link "File exists" /
+# missing-port errors are expected and ignored.
+
+set -u
+
+SC="SuperCollider"
+INTERVAL="${TIDAL_AUTOROUTE_INTERVAL:-2}"
+
+link() {  # $1 = source port, $2 = dest port ; silent (already-linked is fine)
+    pw-link "$1" "$2" 2>/dev/null
+}
+
+# Print the set of Ardour "Tidal NN" track numbers currently present.
+tidal_track_numbers() {
+    pw-link -i 2>/dev/null \
+        | grep -oE "ardour:Tidal [0-9]+/audio_in 1" \
+        | grep -oE "[0-9]+" | sort -un
+}
+
+# Print "src<TAB>dest" for every SuperCollider:out_* -> hardware playback link.
+sc_hw_playback_links() {
+    pw-link -lo 2>/dev/null | awk -v sc="$SC" '
+        /^[^ \t]/ { src = $0; next }                       # non-indented = source port
+        index(src, sc ":out_") == 1 && /playback_/ {       # indented hw-playback dest
+            dst = $0; sub(/^[ \t]*\|?->? */, "", dst);
+            print src "\t" dst
+        }'
+}
+
+reconcile() {
+    # ADD: orbit pair -> matching Tidal track
+    while read -r nn; do
+        [ -n "${nn:-}" ] || continue
+        k=$((10#$nn))                 # strip leading zero (NN -> k)
+        l=$((2 * k - 1)); r=$((2 * k))
+        link "$SC:out_$l" "ardour:Tidal $nn/audio_in 1"
+        link "$SC:out_$r" "ardour:Tidal $nn/audio_in 2"
+    done < <(tidal_track_numbers)
+
+    # PRUNE: SuperCollider must never reach hardware playback directly
+    while IFS=$'\t' read -r src dst; do
+        [ -n "${src:-}" ] && [ -n "${dst:-}" ] && pw-link -d "$src" "$dst" 2>/dev/null
+    done < <(sc_hw_playback_links)
+}
+
+echo "tidal-ardour-autoroute: reconciling orbit->track every ${INTERVAL}s"
+while :; do
+    reconcile
+    sleep "$INTERVAL"
+done