feat(niri-live): dual-kernel boot menu, audio fix, elogind fix, rsync optimization

- Add kernel 7 (linux-mainline) as primary boot entry
- Add kernel 6 (linux) as secondary fallback boot entry
- Simplified boot menu: single entry per kernel, no failsafe variants
- Add snd-intel-dspcfg.dsp_driver=1 + snd_hda_intel.dmic_detect=0 to BOOT_CMDLINE
- Fix elogind sv: dual D-Bus + PID check to suppress already-running warnings
- Replace cp -rfpPv with rsync -aHX in copy_include_directories (nixpkgs speed fix)
- Fix trailing slash bash glob bug in mklive.sh and postsetup-nvidia.sh
- Add -v linux-mainline to _inner-build-niri-live.sh for correct primary kernel

iso/build-niri-live-iso.sh

@@ -205,25 +205,52 @@ install -d -m 0755 "$INCLUDE_DIR/etc/sv/elogind"
 cat > "$INCLUDE_DIR/etc/sv/elogind/run" <<'EOF'
 #!/bin/sh
 exec 2>&1
-# If elogind is already running (e.g. from a previous attempt), stay up
-# permanently rather than letting runit restart the wrapper every 3 s.
-if [ -f /run/elogind.pid ] && kill -0 "$(cat /run/elogind.pid 2>/dev/null)" 2>/dev/null; then
-    echo "elogind-sv: already running (PID $(cat /run/elogind.pid)), yielding"
+
+# Helper: is elogind's login1 D-Bus name already registered on the system bus?
+_login1_on_dbus() {
+    dbus-send --system --print-reply --dest=org.freedesktop.DBus \
+        /org/freedesktop/DBus org.freedesktop.DBus.GetNameOwner \
+        string:org.freedesktop.login1 >/dev/null 2>&1
+}
+
+# Helper: is elogind process alive via its PID file?
+_elogind_alive() {
+    for _pf in /run/elogind.pid /run/elogind/elogind.pid; do
+        [ -f "$_pf" ] && kill -0 "$(cat "$_pf" 2>/dev/null)" 2>/dev/null && return 0
+    done
+    return 1
+}
+
+# If elogind is already running (process alive or D-Bus name taken), yield
+# permanently so runit does not spam restarts.
+if _elogind_alive || _login1_on_dbus; then
+    echo "elogind-sv: already running — yielding to avoid restart spam"
     exec tail -f /dev/null
 fi
+
 # Wait for dbus socket — poll every second, up to 30s
 i=0
 while [ $i -lt 30 ] && [ ! -S /run/dbus/system_bus_socket ]; do
     sleep 1; i=$((i+1))
 done
+
 exec /usr/libexec/elogind/elogind.wrapper
 EOF
 chmod 0755 "$INCLUDE_DIR/etc/sv/elogind/run"
 
-# finish: rate-limit restarts to avoid "already running" spam
+# finish: rate-limit restarts; if the run was very short (elogind crashed or
+# reported "already running" before our detection), back off longer.
 cat > "$INCLUDE_DIR/etc/sv/elogind/finish" <<'EOF'
 #!/bin/sh
-sleep 3
+# $1=exitcode, $2=signal (or -1)
+exitcode="$1"
+# Non-zero exit with no signal = elogind bailed out (e.g. "already running").
+# Sleep longer to avoid log spam; next run will yield via the D-Bus/PID check.
+if [ "$exitcode" != "0" ] && [ "$2" = "-1" ]; then
+    sleep 10
+else
+    sleep 3
+fi
 EOF
 chmod 0755 "$INCLUDE_DIR/etc/sv/elogind/finish"
 
@@ -832,7 +859,7 @@ ISO_PKGS=$(grep -vE '^\s*(#|$)' \
     | tr '\n' ' ')
 TS="$(date -u +%Y%m%d)"
 OUT_ISO="${OUTPUT_ISO:-$OUT_DIR/void-live-niri-${TS}.iso}"
-BOOT_CMDLINE="${BOOT_CMDLINE:-live.user=${LIVE_USER} console=tty0 console=ttyS0,115200 nvidia-drm.modeset=1 rd.driver.blacklist=nouveau modprobe.blacklist=nouveau btusb.enable_autosuspend=0}"
+BOOT_CMDLINE="${BOOT_CMDLINE:-live.user=${LIVE_USER} console=tty0 console=ttyS0,115200 nvidia-drm.modeset=1 rd.driver.blacklist=nouveau modprobe.blacklist=nouveau btusb.enable_autosuspend=0 snd-intel-dspcfg.dsp_driver=1 snd_hda_intel.dmic_detect=0}"
 
 echo ">>> running mklive.sh inside docker — output: $OUT_ISO"
 "$DOCKER" run --rm --privileged \