install: avoid forcing pipewire jack over jack2

scripts/install/client.sh

@@ -312,12 +312,28 @@ MSG
    Good first retry:
      sudo pacman -Syu --disable-download-timeout
    If mirrors keep timing out, refresh /etc/pacman.d/mirrorlist before retrying.
+MSG
+  elif grep -Eq "pipewire-jack.*jack2|jack2.*pipewire-jack|are in conflict \\(jack\\)" "$log_file"; then
+    cat >&2 <<'MSG'
+❌ Arch refused to install pipewire-jack because JACK is already provided by jack2.
+   Lesavka does not require JACK. The installer only keeps pipewire-jack coherent
+   on hosts that already use it; do not remove jack2 just for Lesavka.
+   Pull the latest installer and rerun the Lesavka client install.
 MSG
   fi
   echo "   pacman log: $log_file" >&2
   exit 1
 }
 
+pipewire_package_set() {
+  printf '%s\n' libpipewire pipewire pipewire-audio pipewire-pulse
+  for package in pipewire-alsa pipewire-jack; do
+    if pacman -Q "$package" >/dev/null 2>&1; then
+      printf '%s\n' "$package"
+    fi
+  done
+}
+
 fetch_client_pki_bundle() {
   [[ $CLIENT_PKI_AUTO_FETCH != 0 && $CLIENT_PKI_AUTO_FETCH != false && $CLIENT_PKI_AUTO_FETCH != no ]] || return 1
   [[ $CLIENT_PKI_SSH_SOURCE == *:* ]] || return 1
@@ -386,9 +402,10 @@ fi
 REPO_URL=${REPO_URL:-$DEFAULT_REPO_URL}
 
 log "1. Installing base packages"
+mapfile -t PIPEWIRE_PACKAGES < <(pipewire_package_set)
 pacman_install \
   git rustup protobuf abseil-cpp gcc clang llvm-libs compiler-rt evtest base-devel libpulse \
-  libpipewire pipewire pipewire-audio pipewire-alsa pipewire-jack pipewire-pulse wireplumber \
+  "${PIPEWIRE_PACKAGES[@]}" wireplumber \
   alsa-utils gst-plugin-pipewire \
   gstreamer gst-plugins-base gst-plugins-good gst-plugins-bad gst-plugins-ugly gst-libav \
   wmctrl qt6-tools wl-clipboard xclip xsel desktop-file-utils openssl

scripts/install/server.sh

@@ -948,12 +948,28 @@ MSG
    Good first retry:
      sudo pacman -Syu --disable-download-timeout
    If mirrors keep timing out, refresh /etc/pacman.d/mirrorlist before retrying.
+MSG
+  elif grep -Eq "pipewire-jack.*jack2|jack2.*pipewire-jack|are in conflict \\(jack\\)" "$log_file"; then
+    cat >&2 <<'MSG'
+❌ Arch refused to install pipewire-jack because JACK is already provided by jack2.
+   Lesavka does not require JACK. The installer only keeps pipewire-jack coherent
+   on hosts that already use it; do not remove jack2 just for Lesavka.
+   Pull the latest installer and rerun the Lesavka server install.
 MSG
   fi
   echo "   pacman log: $log_file" >&2
   exit 1
 }
 
+pipewire_package_set() {
+  printf '%s\n' libpipewire pipewire pipewire-audio pipewire-pulse
+  for package in pipewire-alsa pipewire-jack; do
+    if pacman -Q "$package" >/dev/null 2>&1; then
+      printf '%s\n' "$package"
+    fi
+  done
+}
+
 install_verified_executable() {
   local src=$1
   local dest=$2
@@ -1042,18 +1058,14 @@ fi
 REPO_URL=${REPO_URL:-$DEFAULT_REPO_URL}
 
 echo "==> 1a. Base packages"
+mapfile -t PIPEWIRE_PACKAGES < <(pipewire_package_set)
 pacman_install git \
                rustup \
                protobuf \
                abseil-cpp \
                gcc \
                alsa-utils \
-               libpipewire \
+               "${PIPEWIRE_PACKAGES[@]}" \
-               pipewire \
-               pipewire-audio \
-               pipewire-alsa \
-               pipewire-jack \
-               pipewire-pulse \
                tailscale \
                base-devel \
                v4l-utils \

tests/installer/scripts/install/client_install_script_contract.rs

@@ -129,9 +129,15 @@ fn client_install_reports_nvidia_and_open_source_media_routes() {
 fn client_install_treats_pipewire_as_one_coherent_transaction() {
     for expected in [
         "pacman_install()",
-        "libpipewire pipewire pipewire-audio pipewire-alsa pipewire-jack pipewire-pulse",
+        "pipewire_package_set()",
+        "libpipewire pipewire pipewire-audio pipewire-pulse",
+        "for package in pipewire-alsa pipewire-jack",
+        "pacman -Q \"$package\"",
+        "\"${PIPEWIRE_PACKAGES[@]}\"",
         "breaks dependency '.*pipewire",
         "PipeWire packages are at mixed exact versions",
+        "Lesavka does not require JACK",
+        "do not remove jack2 just for Lesavka",
         "sudo pacman -Syu",
         "failed retrieving file",
         "sudo pacman -Syu --disable-download-timeout",

tests/installer/scripts/install/server_install_script_contract.rs

@@ -388,12 +388,15 @@ fn server_install_provisions_non_rebooting_recovery_ladder() {
 fn server_install_treats_pipewire_as_one_coherent_transaction() {
     for expected in [
         "pacman_install()",
-        "libpipewire",
+        "pipewire_package_set()",
-        "pipewire-audio",
+        "libpipewire pipewire pipewire-audio pipewire-pulse",
-        "pipewire-alsa",
+        "for package in pipewire-alsa pipewire-jack",
-        "pipewire-jack",
+        "pacman -Q \"$package\"",
+        "\"${PIPEWIRE_PACKAGES[@]}\"",
         "breaks dependency '.*pipewire",
         "PipeWire packages are at mixed exact versions",
+        "Lesavka does not require JACK",
+        "do not remove jack2 just for Lesavka",
         "failed retrieving file",
         "sudo pacman -Syu --disable-download-timeout",
     ] {