diff --git a/README.md b/README.md
index 2f01478..d936365 100644
--- a/README.md
+++ b/README.md
@@ -117,6 +117,16 @@ Volumio-spezifisch:
 /home/volumio/phoenix.log
 ```
 
+Die Volumio-spezifischen Units, der eingeschränkte Update-Helfer und die
+zugehörige sudo-Regel werden einmalig als root installiert:
+
+```bash
+sudo bash /home/volumio/Phoenix/scripts/install_volumio_services.sh
+```
+
+Der Installer verändert keine Debian-/Analyzer-Units und startet laufende
+Dienste nicht automatisch neu.
+
 Wenn `toggle-ext` genutzt werden soll, sollte es also unter diesem Pfad liegen:
 
 ```text
diff --git a/etc/sudoers.d/phoenix-update-volumio b/etc/sudoers.d/phoenix-update-volumio
new file mode 100644
index 0000000..77f055f
--- /dev/null
+++ b/etc/sudoers.d/phoenix-update-volumio
@@ -0,0 +1 @@
+volumio ALL=(root) NOPASSWD: /usr/bin/systemctl --no-block start phoenix-update-volumio.service
diff --git a/etc/systemd/system/phoenix-update-volumio.service b/etc/systemd/system/phoenix-update-volumio.service
new file mode 100644
index 0000000..691ef32
--- /dev/null
+++ b/etc/systemd/system/phoenix-update-volumio.service
@@ -0,0 +1,15 @@
+[Unit]
+Description=Apply staged Phoenix update on Volumio
+After=local-fs.target
+
+[Service]
+Type=oneshot
+User=root
+Group=root
+TimeoutStartSec=30min
+Nice=10
+IOSchedulingClass=idle
+Environment=PHOENIX_INSTALL_PROFILE=volumio
+Environment=PHOENIX_UPDATE_DETACHED=1
+Environment=PHOENIX_ROOT_OVERRIDE=/home/volumio/Phoenix
+ExecStart=/bin/bash /usr/local/libexec/phoenix/restart_phoenix_services.sh
diff --git a/scripts/install_volumio_services.sh b/scripts/install_volumio_services.sh
new file mode 100755
index 0000000..1427fed
--- /dev/null
+++ b/scripts/install_volumio_services.sh
@@ -0,0 +1,58 @@
+#!/bin/bash
+
+set -euo pipefail
+
+if [ "$(id -u)" -ne 0 ]; then
+  echo "run this installer as root" >&2
+  exit 1
+fi
+
+SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd -P)"
+PHOENIX_ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
+SYSTEMD_SOURCE="$PHOENIX_ROOT/etc/systemd/system"
+SUDOERS_SOURCE="$PHOENIX_ROOT/etc/sudoers.d/phoenix-update-volumio"
+LIBEXEC_DIR="/usr/local/libexec/phoenix"
+
+required_files=(
+  "$SYSTEMD_SOURCE/analyzer-kiosk-volumio.service"
+  "$SYSTEMD_SOURCE/analyzer-web-volumio.service"
+  "$SYSTEMD_SOURCE/phoenix-update-volumio.service"
+  "$SUDOERS_SOURCE"
+  "$PHOENIX_ROOT/scripts/restart_phoenix_services.sh"
+)
+
+for path in "${required_files[@]}"; do
+  if [ ! -f "$path" ]; then
+    echo "required Volumio integration file missing: $path" >&2
+    exit 1
+  fi
+done
+
+if ! command -v visudo >/dev/null 2>&1; then
+  echo "visudo not found; refusing to install sudo policy" >&2
+  exit 1
+fi
+visudo -cf "$SUDOERS_SOURCE"
+
+install -d -o root -g root -m 0755 "$LIBEXEC_DIR"
+install -o root -g root -m 0755 \
+  "$PHOENIX_ROOT/scripts/restart_phoenix_services.sh" \
+  "$LIBEXEC_DIR/restart_phoenix_services.sh"
+install -o root -g root -m 0644 \
+  "$SYSTEMD_SOURCE/analyzer-kiosk-volumio.service" \
+  /etc/systemd/system/analyzer-kiosk-volumio.service
+install -o root -g root -m 0644 \
+  "$SYSTEMD_SOURCE/analyzer-web-volumio.service" \
+  /etc/systemd/system/analyzer-web-volumio.service
+install -o root -g root -m 0644 \
+  "$SYSTEMD_SOURCE/phoenix-update-volumio.service" \
+  /etc/systemd/system/phoenix-update-volumio.service
+install -o root -g root -m 0440 \
+  "$SUDOERS_SOURCE" \
+  /etc/sudoers.d/phoenix-update-volumio
+
+systemctl daemon-reload
+systemctl enable analyzer-web-volumio.service analyzer-kiosk-volumio.service
+
+echo "Volumio integration installed"
+echo "Existing services were not restarted"
diff --git a/scripts/restart_phoenix_services.sh b/scripts/restart_phoenix_services.sh
index 6af857d..9c4422f 100644
--- a/scripts/restart_phoenix_services.sh
+++ b/scripts/restart_phoenix_services.sh
@@ -3,7 +3,12 @@
 set -euo pipefail
 
 SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd -P)"
-PHOENIX_ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
+PHOENIX_ROOT="${PHOENIX_ROOT_OVERRIDE:-}"
+if [ -z "$PHOENIX_ROOT" ]; then
+  PHOENIX_ROOT="$(cd "$SCRIPT_DIR/.." && pwd -P)"
+else
+  PHOENIX_ROOT="$(cd "$PHOENIX_ROOT" && pwd -P)"
+fi
 PHOENIX_PARENT="$(cd "$PHOENIX_ROOT/.." && pwd -P)"
 PHOENIX_NAME="$(basename "$PHOENIX_ROOT")"
 STAGE_DIR="$PHOENIX_PARENT/${PHOENIX_NAME}.update"
@@ -14,6 +19,10 @@ LOG_FILE="$PHOENIX_PARENT/${PHOENIX_NAME}.update.log"
 exec >>"$LOG_FILE" 2>&1
 echo "=== $(date): restart_phoenix_services.sh START ==="
 
+is_volumio_install() {
+  [ "${PHOENIX_INSTALL_PROFILE:-}" = "volumio" ] || [ "$PHOENIX_ROOT" = "/home/volumio/Phoenix" ]
+}
+
 restart_if_present() {
   local unit="$1"
   if ! command -v systemctl >/dev/null 2>&1; then
@@ -61,6 +70,19 @@ run_systemd_run() {
     /usr/bin/env PHOENIX_UPDATE_DETACHED=1 /bin/bash "$0"
 }
 
+start_volumio_update_service() {
+  local unit="phoenix-update-volumio.service"
+  if [ "$(id -u)" -eq 0 ]; then
+    /usr/bin/systemctl --no-block start "$unit"
+    return $?
+  fi
+  if ! command -v sudo >/dev/null 2>&1; then
+    echo "sudo not found; cannot start $unit as non-root" >&2
+    return 1
+  fi
+  sudo -n /usr/bin/systemctl --no-block start "$unit"
+}
+
 health_ok() {
   if ! command -v curl >/dev/null 2>&1; then
     return 0
@@ -144,7 +166,56 @@ wait_for_candidate_health() {
   return 1
 }
 
+build_volumio_candidate() {
+  local phoenix_dir="${1:-$STAGE_DIR}"
+  local cargo_bin=""
+  local cargo_dir=""
+  local candidate
+
+  if ! needs_phoenix_build "$phoenix_dir"; then
+    echo "Volumio candidate already contains a runnable Phoenix binary"
+    return 0
+  fi
+
+  for candidate in /root/.cargo/bin/cargo /home/volumio/.cargo/bin/cargo /usr/local/bin/cargo /usr/bin/cargo; do
+    if [ -x "$candidate" ]; then
+      cargo_bin="$candidate"
+      break
+    fi
+  done
+  if [ -z "$cargo_bin" ]; then
+    echo "cargo not found; cannot build staged Volumio update" >&2
+    return 1
+  fi
+  cargo_dir="$(dirname "$cargo_bin")"
+
+  echo "building staged Volumio update before stopping the running kiosk"
+  if ! (
+    cd "$phoenix_dir"
+    PATH="$cargo_dir:/root/.cargo/bin:/home/volumio/.cargo/bin:/usr/local/bin:/usr/bin:/bin" \
+      CARGO_TERM_COLOR=never "$cargo_bin" build --release --locked
+  ); then
+    if [ -d "$phoenix_dir/target" ]; then
+      chown -R volumio:volumio "$phoenix_dir/target" || true
+    fi
+    echo "staged Volumio build failed; running installation was left untouched" >&2
+    return 1
+  fi
+  chown -R volumio:volumio "$phoenix_dir/target"
+  if [ ! -x "$phoenix_dir/target/release/phoenix" ] || [ ! -s "$phoenix_dir/target/release/phoenix" ]; then
+    echo "staged Volumio build did not produce a runnable Phoenix binary" >&2
+    return 1
+  fi
+  echo "staged Volumio build completed"
+}
+
 start_all_services() {
+  if is_volumio_install; then
+    restart_if_present analyzer-web-volumio.service
+    clear_browser_asset_caches
+    restart_if_present analyzer-kiosk-volumio.service
+    return
+  fi
   restart_if_present phoenix.service
   restart_if_present analyzer-web.service
   restart_if_present analyzer-web-volumio.service
@@ -154,6 +225,11 @@ start_all_services() {
 }
 
 stop_all_services() {
+  if is_volumio_install; then
+    stop_if_present analyzer-kiosk-volumio.service
+    stop_if_present analyzer-web-volumio.service
+    return
+  fi
   stop_if_present analyzer-kiosk.service
   stop_if_present analyzer-kiosk-volumio.service
   stop_if_present analyzer-web.service
@@ -180,6 +256,16 @@ rollback_to_backup() {
 }
 
 if [ "${PHOENIX_UPDATE_DETACHED:-0}" != "1" ]; then
+  if is_volumio_install; then
+    echo "handing Volumio update to phoenix-update-volumio.service"
+    if start_volumio_update_service; then
+      echo "Volumio update service accepted"
+      exit 0
+    fi
+    echo "failed to start phoenix-update-volumio.service" >&2
+    echo "run scripts/install_volumio_services.sh once as root" >&2
+    exit 1
+  fi
   if ! command -v systemd-run >/dev/null 2>&1; then
     echo "systemd-run not found; cannot safely detach updater" >&2
     exit 1
@@ -202,6 +288,10 @@ if [ ! -f "$STAGE_DIR/Cargo.toml" ] || [ ! -d "$STAGE_DIR/src" ] || [ ! -d "$STA
   exit 1
 fi
 
+if is_volumio_install; then
+  build_volumio_candidate "$STAGE_DIR"
+fi
+
 stop_all_services
 
 rm -rf "$BACKUP_DIR"
@@ -222,4 +312,11 @@ if ! wait_for_candidate_health "$PHOENIX_ROOT" "$health_attempts" "$health_delay
   exit 1
 fi
 
+if is_volumio_install && [ "$(id -u)" -eq 0 ] && [ -f "$PHOENIX_ROOT/scripts/restart_phoenix_services.sh" ]; then
+  install -o root -g root -m 0755 \
+    "$PHOENIX_ROOT/scripts/restart_phoenix_services.sh" \
+    /usr/local/libexec/phoenix/restart_phoenix_services.sh
+  echo "Volumio privileged update helper refreshed"
+fi
+
 echo "=== $(date): restart_phoenix_services.sh OK ==="
diff --git a/session_volumio.sh b/session_volumio.sh
index 397314e..17bbb9c 100644
--- a/session_volumio.sh
+++ b/session_volumio.sh
@@ -165,10 +165,6 @@ else
   chmod 700 "$CHROME_USER_DATA_DIR"
 fi
 
-pkill -9 -x chromium || true
-pkill -9 -f "chromium.*--kiosk" || true
-sleep 0.3
-
 EXTENSIONS=()
 EXT_VK_RESOLVED="$(resolve_extension_dir "$EXT_VK" \
   "$PHOENIX_DIR/VirtualKeyboard" \
@@ -216,21 +212,18 @@ CHROME_CMD=(
   --disable-features=Translate,TranslateUI
   --memory-pressure-off
   --max-active-webgl-contexts=1
-  "$ANALYZER_URL"
-  "$VOLUMIO_URL"
 )
 
 if [ -n "$EXTENSION_ARG" ]; then
   CHROME_CMD+=(--load-extension="$EXTENSION_ARG")
 fi
 
+# Start with the lightweight Analyzer page. The tab-toggle extension creates
+# exactly one inactive Volumio tab after Chromium is ready.
+CHROME_CMD+=("$ANALYZER_URL")
+
 sudo -u "$KIOSK_USER" "${CHROME_CMD[@]}" >>"$LOG" 2>&1 &
 CHROME_PID=$!
 
-sleep 2
-if command -v xdotool >/dev/null 2>&1; then
-  xdotool key Ctrl+t type "$VOLUMIO_URL" key Return || true
-fi
-
 wait "$CHROME_PID"
 echo "=== $(date): session_volumio.sh END ==="
diff --git a/toggle-ext/bg.js b/toggle-ext/bg.js
index e9cc7c3..597c193 100644
--- a/toggle-ext/bg.js
+++ b/toggle-ext/bg.js
@@ -1,16 +1,45 @@
-// Aktiviert den bestehenden Tab mit Ziel-URL (ohne Reload). Falls nicht offen, wird er geöffnet.
+const ANALYZER_URL = 'http://localhost:8088/';
+const VOLUMIO_URL = 'http://localhost:3000/';
+
+function matchingTabs(tabs, url) {
+  return tabs.filter(tab => tab.url && tab.url.startsWith(url));
+}
+
+// Keep one Analyzer and one Volumio tab. Chromium starts on Analyzer, so
+// Volumio can load in the background without delaying the first visible UI.
+function ensureDualTabs() {
+  chrome.tabs.query({ currentWindow: true }, tabs => {
+    const analyzerTabs = matchingTabs(tabs, ANALYZER_URL);
+    const volumioTabs = matchingTabs(tabs, VOLUMIO_URL);
+    const duplicates = [...analyzerTabs.slice(1), ...volumioTabs.slice(1)]
+      .map(tab => tab.id)
+      .filter(id => Number.isInteger(id));
+
+    if (duplicates.length > 0) chrome.tabs.remove(duplicates);
+    if (analyzerTabs.length === 0) chrome.tabs.create({ url: ANALYZER_URL, active: true });
+    if (volumioTabs.length === 0) chrome.tabs.create({ url: VOLUMIO_URL, active: false });
+  });
+}
+
+// Activate an existing application tab without reloading it.
 function activateOrCreate(url) {
-  chrome.tabs.query({}, tabs => {
-    const t = tabs.find(tt => tt.url && tt.url.startsWith(url));
-    if (t) { chrome.tabs.update(t.id, {active: true}); }
-    else   { chrome.tabs.create({url}); }
+  chrome.tabs.query({ currentWindow: true }, tabs => {
+    const tab = matchingTabs(tabs, url)[0];
+    if (tab) chrome.tabs.update(tab.id, { active: true });
+    else chrome.tabs.create({ url, active: true });
   });
 }
 
 chrome.runtime.onMessage.addListener((msg, _sender, sendResponse) => {
-  if (msg && msg.cmd === 'toggle') {
-    if (msg.from === 'volumio') activateOrCreate('http://localhost:8088/');
-    else                        activateOrCreate('http://localhost:3000/');
-    sendResponse({ok:true});
+  if (!msg) return;
+  if (msg.cmd === 'bootstrap') {
+    ensureDualTabs();
+    sendResponse({ ok: true });
+    return;
+  }
+  if (msg.cmd === 'toggle') {
+    if (msg.from === 'volumio') activateOrCreate(ANALYZER_URL);
+    else activateOrCreate(VOLUMIO_URL);
+    sendResponse({ ok: true });
   }
 });
diff --git a/toggle-ext/content.js b/toggle-ext/content.js
index 88aeac6..36e459c 100644
--- a/toggle-ext/content.js
+++ b/toggle-ext/content.js
@@ -1 +1,40 @@
-(function(){try{const e="3000"===location.port,t=document.createElement("button");function o(){chrome.runtime.sendMessage({cmd:"toggle",from:e?"volumio":"analyzer"},(()=>{}))}t.textContent=e?"Analyzer":"Volumio",Object.assign(t.style,{position:"fixed",right:"10px",top:"10px",zIndex:999999,font:"bold 14px ui-monospace,monospace",padding:"6px 10px",background:"#0b0b12",color:"#ddd",border:"1px solid #333",borderRadius:"8px",cursor:"pointer",opacity:"0.85"}),t.onmouseenter=()=>t.style.opacity="1",t.onmouseleave=()=>t.style.opacity="0.85",t.onclick=o,document.body.appendChild(t),window.addEventListener("keydown",(t=>{"t"===t.key.toLowerCase()&&(t.preventDefault(),o())}),{capture:!0})}catch(e){}})();
+(function () {
+  try {
+    const isVolumio = location.port === '3000';
+    const button = document.createElement('button');
+    const toggle = () => {
+      chrome.runtime.sendMessage(
+        { cmd: 'toggle', from: isVolumio ? 'volumio' : 'analyzer' },
+        () => {},
+      );
+    };
+
+    chrome.runtime.sendMessage({ cmd: 'bootstrap' }, () => {});
+
+    button.textContent = isVolumio ? 'Analyzer' : 'Volumio';
+    Object.assign(button.style, {
+      position: 'fixed',
+      right: '10px',
+      top: '10px',
+      zIndex: 999999,
+      font: 'bold 14px ui-monospace,monospace',
+      padding: '6px 10px',
+      background: '#0b0b12',
+      color: '#ddd',
+      border: '1px solid #333',
+      borderRadius: '8px',
+      cursor: 'pointer',
+      opacity: '0.85',
+    });
+    button.onmouseenter = () => { button.style.opacity = '1'; };
+    button.onmouseleave = () => { button.style.opacity = '0.85'; };
+    button.onclick = toggle;
+    document.body.appendChild(button);
+    window.addEventListener('keydown', event => {
+      if (event.key.toLowerCase() === 't') {
+        event.preventDefault();
+        toggle();
+      }
+    }, { capture: true });
+  } catch (_) {}
+})();