diff --git a/electron/main.ts b/electron/main.ts
index 27a25d5..79c1306 100644
--- a/electron/main.ts
+++ b/electron/main.ts
@@ -28,8 +28,22 @@ function findPythonCmd(projectRoot: string): string {
   return "python3";
 }
 
+const EXTRA_PATH_DIRS = [
+  "/usr/bin",
+  "/usr/local/bin",
+  "/var/usrlocal/bin",
+  "/usr/lib/extensions/vulkan/MangoHud/bin",
+  "/usr/lib64/extensions/vulkan/MangoHud/bin",
+  "/run/current-system/sw/bin", // NixOS
+].join(":");
+
 function getPythonCommand(): { cmd: string; args: string[]; env: NodeJS.ProcessEnv } {
   const env = { ...process.env };
+  // Immutable distros (Bazzite, SteamOS, Fedora Atomic) and AppImage
+  // wrappers can strip PATH entries. Ensure common locations are present.
+  if (env.PATH && !env.PATH.includes("/var/usrlocal/bin")) {
+    env.PATH = `${env.PATH}:${EXTRA_PATH_DIRS}`;
+  }
 
   if (isDev) {
     const projectRoot = path.resolve(__dirname, "..", "..");
diff --git a/electron/package.json b/electron/package.json
index 76ae4e1..9616e6b 100644
--- a/electron/package.json
+++ b/electron/package.json
@@ -1,6 +1,6 @@
 {
   "name": "protonshift",
-  "version": "0.8.8",
+  "version": "0.8.9",
   "description": "Linux game configuration toolkit",
   "main": "dist/main.js",
   "scripts": {
diff --git a/electron/renderer/src/app/mangohud/page.tsx b/electron/renderer/src/app/mangohud/page.tsx
index 017b792..f83df67 100644
--- a/electron/renderer/src/app/mangohud/page.tsx
+++ b/electron/renderer/src/app/mangohud/page.tsx
@@ -203,8 +203,9 @@ export default function MangoHudPage() {
               <p className="text-xs text-text-secondary font-medium">Install via your package manager:</p>
               <div className="grid grid-cols-1 sm:grid-cols-2 gap-2">
                 {[
+                  { distro: "Bazzite / SteamOS", cmd: "Pre-installed — restart app or check PATH" },
                   { distro: "Ubuntu / Pop!_OS / Mint", cmd: "sudo apt install mangohud" },
-                  { distro: "Fedora", cmd: "sudo dnf install mangohud" },
+                  { distro: "Fedora / Fedora Atomic", cmd: "sudo dnf install mangohud" },
                   { distro: "Arch / Manjaro / EndeavourOS", cmd: "sudo pacman -S mangohud" },
                   { distro: "openSUSE", cmd: "sudo zypper install mangohud" },
                   { distro: "Flatpak (Steam)", cmd: "flatpak install flathub org.freedesktop.Platform.VulkanLayer.MangoHud" },
diff --git a/electron/renderer/src/components/gamescope-builder.tsx b/electron/renderer/src/components/gamescope-builder.tsx
index 5d9780e..6c597e0 100644
--- a/electron/renderer/src/components/gamescope-builder.tsx
+++ b/electron/renderer/src/components/gamescope-builder.tsx
@@ -114,8 +114,9 @@ export function GamescopeBuilder({ onInsert }: GamescopeBuilderProps) {
           <p className="text-xs text-text-secondary font-medium">Install via your package manager:</p>
           <div className="grid grid-cols-1 sm:grid-cols-2 gap-1.5">
             {[
+              { distro: "Bazzite / SteamOS", cmd: "Pre-installed — restart app or check PATH" },
               { distro: "Arch / Manjaro / EndeavourOS", cmd: "sudo pacman -S gamescope" },
-              { distro: "Fedora", cmd: "sudo dnf install gamescope" },
+              { distro: "Fedora / Fedora Atomic", cmd: "sudo dnf install gamescope" },
               { distro: "openSUSE", cmd: "sudo zypper install gamescope" },
               { distro: "NixOS", cmd: "nix-env -iA nixpkgs.gamescope" },
               { distro: "Flatpak (Steam)", cmd: "Bundled with Steam Flatpak" },
diff --git a/pyproject.toml b/pyproject.toml
index a89465b..1fbdeb4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "protonshift"
-version = "0.8.8"
+version = "0.8.9"
 description = "Linux game configuration toolkit: GPU, launch options, Proton, env vars"
 readme = "README.md"
 requires-python = ">=3.12"
diff --git a/src/game_setup_hub/display.py b/src/game_setup_hub/display.py
index 4908c7e..3901a5f 100644
--- a/src/game_setup_hub/display.py
+++ b/src/game_setup_hub/display.py
@@ -4,10 +4,11 @@
 
 import os
 import re
-import shutil
 import subprocess
 from dataclasses import dataclass
 
+from game_setup_hub.tool_check import find_tool
+
 
 @dataclass
 class MonitorInfo:
@@ -33,11 +34,12 @@ def get_session_type() -> str:
 
 def _parse_xrandr() -> list[MonitorInfo]:
     """Parse xrandr output for connected monitors."""
-    if not shutil.which("xrandr"):
+    xrandr = find_tool("xrandr")
+    if not xrandr:
         return []
     try:
         result = subprocess.run(
-            ["xrandr", "--current"],
+            [xrandr, "--current"],
             capture_output=True,
             text=True,
             timeout=5,
@@ -93,11 +95,12 @@ def _parse_xrandr() -> list[MonitorInfo]:
 
 def _parse_wlr_randr() -> list[MonitorInfo]:
     """Parse wlr-randr output for Wayland monitors."""
-    if not shutil.which("wlr-randr"):
+    wlr_randr = find_tool("wlr-randr")
+    if not wlr_randr:
         return []
     try:
         result = subprocess.run(
-            ["wlr-randr"],
+            [wlr_randr],
             capture_output=True,
             text=True,
             timeout=5,
@@ -158,9 +161,10 @@ def get_monitors() -> list[MonitorInfo]:
 
 def set_resolution(monitor: str, width: int, height: int, refresh: float = 0) -> bool:
     """Set resolution for a monitor using xrandr. Returns True on success."""
-    if not shutil.which("xrandr"):
+    xrandr = find_tool("xrandr")
+    if not xrandr:
         return False
-    cmd = ["xrandr", "--output", monitor, "--mode", f"{width}x{height}"]
+    cmd = [xrandr, "--output", monitor, "--mode", f"{width}x{height}"]
     if refresh > 0:
         cmd.extend(["--rate", str(refresh)])
     try:
diff --git a/src/game_setup_hub/gamescope.py b/src/game_setup_hub/gamescope.py
index 1d6fab9..bcf31b8 100644
--- a/src/game_setup_hub/gamescope.py
+++ b/src/game_setup_hub/gamescope.py
@@ -2,9 +2,10 @@
 
 from __future__ import annotations
 
-import shutil
 from dataclasses import dataclass
 
+from game_setup_hub.tool_check import is_tool_available
+
 
 @dataclass
 class GamescopeOptions:
@@ -25,7 +26,7 @@ class GamescopeOptions:
 
 def is_gamescope_available() -> bool:
     """Check if gamescope is installed."""
-    return shutil.which("gamescope") is not None
+    return is_tool_available("gamescope")
 
 
 def build_gamescope_cmd(opts: GamescopeOptions) -> str:
diff --git a/src/game_setup_hub/mangohud.py b/src/game_setup_hub/mangohud.py
index f4d6871..df411bd 100644
--- a/src/game_setup_hub/mangohud.py
+++ b/src/game_setup_hub/mangohud.py
@@ -2,9 +2,10 @@
 
 from __future__ import annotations
 
-import shutil
 from pathlib import Path
 
+from game_setup_hub.tool_check import is_tool_available
+
 MANGOHUD_CONFIG_DIR = Path.home() / ".config" / "MangoHud"
 MANGOHUD_GLOBAL_CONF = MANGOHUD_CONFIG_DIR / "MangoHud.conf"
 
@@ -166,7 +167,7 @@
 
 def is_mangohud_available() -> bool:
     """Check if MangoHud is installed."""
-    return shutil.which("mangohud") is not None
+    return is_tool_available("mangohud")
 
 
 def read_mangohud_config(path: Path | None = None) -> dict[str, str]:
diff --git a/src/game_setup_hub/presets.py b/src/game_setup_hub/presets.py
index 1373a46..93bb556 100644
--- a/src/game_setup_hub/presets.py
+++ b/src/game_setup_hub/presets.py
@@ -2,9 +2,10 @@
 
 from __future__ import annotations
 
-import shutil
 from dataclasses import dataclass
 
+from game_setup_hub.tool_check import is_tool_available
+
 
 @dataclass
 class LaunchPreset:
@@ -19,20 +20,10 @@ class LaunchPreset:
     def is_installed(self) -> bool:
         """Check if the tool/feature is available."""
         if self.value == "gamemoderun":
-            return _check_gamemode()
+            return is_tool_available("gamemoderun")
         if "MANGOHUD" in self.value:
-            return _check_mangohud()
-        return True  # No check for env vars, Proton Log, NVIDIA dGPU
-
-
-def _check_gamemode() -> bool:
-    """Check if gamemode is installed."""
-    return shutil.which("gamemoderun") is not None
-
-
-def _check_mangohud() -> bool:
-    """Check if MangoHud is installed."""
-    return shutil.which("mangohud") is not None
+            return is_tool_available("mangohud")
+        return True
 
 
 LAUNCH_PRESETS: list[LaunchPreset] = [
diff --git a/src/game_setup_hub/protontricks.py b/src/game_setup_hub/protontricks.py
index 7f47d2b..ab9d6fc 100644
--- a/src/game_setup_hub/protontricks.py
+++ b/src/game_setup_hub/protontricks.py
@@ -2,9 +2,10 @@
 
 from __future__ import annotations
 
-import shutil
 import subprocess
 
+from game_setup_hub.tool_check import find_tool
+
 
 PROTONTRICKS_FLATPAK = "com.github.Matoking.protontricks"
 
@@ -20,7 +21,7 @@
 
 def is_protontricks_available() -> bool:
     """Check if Protontricks is available (native or Flatpak)."""
-    if shutil.which("protontricks"):
+    if find_tool("protontricks"):
         return True
     try:
         r = subprocess.run(
@@ -39,8 +40,9 @@ def get_protontricks_cmd(app_id: str, verb: str | None = None) -> list[str] | No
     Returns [cmd, ...args] or None if not available.
     If verb is None, opens GUI (--gui).
     """
-    if shutil.which("protontricks"):
-        cmd = ["protontricks", app_id]
+    pt = find_tool("protontricks")
+    if pt:
+        cmd = [pt, app_id]
         if verb:
             cmd.append(verb)
         else:
diff --git a/src/game_setup_hub/tool_check.py b/src/game_setup_hub/tool_check.py
new file mode 100644
index 0000000..746469f
--- /dev/null
+++ b/src/game_setup_hub/tool_check.py
@@ -0,0 +1,93 @@
+"""Unified tool detection with fallback paths for immutable distros.
+
+On Bazzite, SteamOS, Fedora Atomic (Kinoite/Silverblue), NixOS, and
+Flatpak-installed tools, binaries often live outside the default PATH
+that shutil.which() searches.  This module provides a single
+``find_tool()`` helper that first tries the normal PATH lookup, then
+probes well-known fallback locations.
+"""
+
+from __future__ import annotations
+
+import os
+import shutil
+from functools import lru_cache
+from pathlib import Path
+
+_EXTRA_BIN_DIRS: tuple[str, ...] = (
+    "/usr/bin",
+    "/usr/local/bin",
+    "/usr/games",
+    "/var/usrlocal/bin",
+    # Flatpak host extensions / SDK merge dirs
+    "/usr/lib/extensions/vulkan/MangoHud/bin",
+    "/usr/lib64/extensions/vulkan/MangoHud/bin",
+    # NixOS profile links
+    os.path.expanduser("~/.nix-profile/bin"),
+    "/run/current-system/sw/bin",
+    # Homebrew / Linuxbrew
+    "/home/linuxbrew/.linuxbrew/bin",
+)
+
+_TOOL_SPECIFIC_PATHS: dict[str, tuple[str, ...]] = {
+    "gamescope": (
+        "/usr/bin/gamescope",
+        "/usr/local/bin/gamescope",
+        "/usr/lib/extensions/gamescope/bin/gamescope",
+    ),
+    "mangohud": (
+        "/usr/bin/mangohud",
+        "/usr/local/bin/mangohud",
+        "/usr/lib/extensions/vulkan/MangoHud/bin/mangohud",
+        "/usr/lib64/extensions/vulkan/MangoHud/bin/mangohud",
+    ),
+    "gamemoderun": (
+        "/usr/bin/gamemoderun",
+        "/usr/local/bin/gamemoderun",
+        "/usr/lib/extensions/gamemode/bin/gamemoderun",
+    ),
+    "protontricks": (
+        "/usr/bin/protontricks",
+        "/usr/local/bin/protontricks",
+        os.path.expanduser("~/.local/bin/protontricks"),
+    ),
+    "xrandr": (
+        "/usr/bin/xrandr",
+        "/usr/local/bin/xrandr",
+    ),
+    "wlr-randr": (
+        "/usr/bin/wlr-randr",
+        "/usr/local/bin/wlr-randr",
+    ),
+}
+
+
+@lru_cache(maxsize=32)
+def find_tool(name: str) -> str | None:
+    """Locate a tool binary, returning the absolute path or ``None``.
+
+    1. ``shutil.which(name)`` — uses the current process PATH.
+    2. ``shutil.which(name, path=...)`` — searches extra bin directories
+       common on immutable/atomic distros.
+    3. Direct file existence checks for tool-specific known paths.
+    """
+    found = shutil.which(name)
+    if found:
+        return found
+
+    extra_path = os.pathsep.join(_EXTRA_BIN_DIRS)
+    found = shutil.which(name, path=extra_path)
+    if found:
+        return found
+
+    for candidate in _TOOL_SPECIFIC_PATHS.get(name, ()):
+        p = Path(candidate)
+        if p.is_file() and os.access(p, os.X_OK):
+            return str(p)
+
+    return None
+
+
+def is_tool_available(name: str) -> bool:
+    """Return True if *name* can be found anywhere on the system."""
+    return find_tool(name) is not None