Install Linux app icon into hicolor theme

The launcher entry previously referenced the app icon by absolute path
(Icon=/.../assets/icon.png). When that PNG is replaced in-place between
builds, GNOME and several other launchers keep showing the *original*
cached image because their thumbnail cache doesn't reliably invalidate
on path+mtime alone — which is what just happened with the v1.2.2 icon
swap on the dev machine.

Fix: install the icon into the user's hicolor icon theme at
~/.local/share/icons/hicolor/256x256/apps/redalert.png and reference it
by themed name (Icon=redalert) in the .desktop file. Themed icons go
through the icon-theme cache, which we also nudge with a best-effort
gtk-update-icon-cache call. Falls back to the absolute-path form if
the theme install fails for any reason.

Also fires update-desktop-database after writing the launcher entry.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: OptimusLinux

src/autoStart.js

@@ -1,4 +1,5 @@
-import { writeFileSync, unlinkSync, existsSync, mkdirSync, readFileSync } from 'fs';
+import { writeFileSync, unlinkSync, existsSync, mkdirSync, readFileSync, copyFileSync } from 'fs';
+import { execFile } from 'child_process';
 import { join, dirname } from 'path';
 import { fileURLToPath } from 'url';
 import { homedir } from 'os';
@@ -72,27 +73,81 @@ function setAutoStartWindows(enabled) {
   log.info(`Windows auto-start ${enabled ? 'enabled' : 'disabled'} (managed by installer)`);
 }
 
+/**
+ * Installs the app icon into the user's hicolor icon theme so launchers can
+ * find it by name. We install at every standard size we have available
+ * (just the 256x256 source — desktop environments will downscale as needed).
+ *
+ * Using a themed icon (referenced as `Icon=redalert` in the .desktop file)
+ * avoids a nasty cache trap: when the .desktop file references an absolute
+ * PNG path and that PNG is later replaced in-place, GNOME / many launchers
+ * keep showing the *original* image because their thumbnail cache is keyed
+ * by path+mtime in a way that doesn't always invalidate. Themed icons go
+ * through the icon-theme cache, which is rebuilt on demand.
+ */
+function installLinuxAppIcon() {
+  const sourceIcon = join(appDir, 'assets', 'icon.png');
+  if (!existsSync(sourceIcon)) {
+    log.warn('App icon source not found, skipping theme install:', sourceIcon);
+    return false;
+  }
+
+  const iconsRoot = join(process.env.XDG_DATA_HOME || join(homedir(), '.local', 'share'), 'icons', 'hicolor');
+  const targetDir = join(iconsRoot, '256x256', 'apps');
+  const targetIcon = join(targetDir, 'redalert.png');
+
+  try {
+    mkdirSync(targetDir, { recursive: true });
+    // Only copy if missing or contents differ, to avoid disk churn on every start.
+    let needsCopy = true;
+    if (existsSync(targetIcon)) {
+      try {
+        const a = readFileSync(sourceIcon);
+        const b = readFileSync(targetIcon);
+        if (a.equals(b)) needsCopy = false;
+      } catch {}
+    }
+    if (needsCopy) {
+      copyFileSync(sourceIcon, targetIcon);
+      log.info('App icon installed into hicolor theme:', targetIcon);
+      // Best-effort icon-cache refresh; failure is fine (not all desktops have it).
+      execFile('gtk-update-icon-cache', ['-f', '-t', iconsRoot], (err) => {
+        if (err) log.info('gtk-update-icon-cache not available or failed (non-critical)');
+      });
+    }
+    return true;
+  } catch (e) {
+    log.warn('Failed to install app icon into hicolor theme:', e.message);
+    return false;
+  }
+}
+
 /**
  * Installs a desktop launcher entry on Linux so RedAlert appears in the
  * applications menu / launcher. Idempotent — safe to call on every startup.
  */
 export function installLinuxLauncher() {
   if (!isLinux) return;
 
+  // Install the icon into the hicolor theme first so we can reference it by name.
+  const iconInstalled = installLinuxAppIcon();
+
   const appsDir = join(process.env.XDG_DATA_HOME || join(homedir(), '.local', 'share'), 'applications');
   const desktopPath = join(appsDir, 'redalert.desktop');
 
   const execPath = process.pkg
     ? process.execPath
     : `${process.execPath} ${join(appDir, 'src', 'main.js')}`;
-  const iconPath = join(appDir, 'assets', 'icon.png');
+  // Prefer themed icon name if we successfully installed it, otherwise fall back
+  // to the absolute path so the entry still has *some* icon.
+  const iconRef = iconInstalled ? 'redalert' : join(appDir, 'assets', 'icon.png');
 
   const desktopEntry = `[Desktop Entry]
 Type=Application
 Name=RedAlert
 Comment=Pikud HaOref alert monitor
 Exec=${execPath}
-Icon=${iconPath}
+Icon=${iconRef}
 Terminal=false
 Categories=Utility;Network;
 StartupNotify=false
@@ -111,6 +166,10 @@ StartupNotify=false
     if (needsWrite) {
       writeFileSync(desktopPath, desktopEntry);
       log.info('Launcher entry installed:', desktopPath);
+      // Best-effort desktop database refresh.
+      execFile('update-desktop-database', [appsDir], (err) => {
+        if (err) log.info('update-desktop-database not available or failed (non-critical)');
+      });
     }
   } catch (e) {
     log.warn('Failed to install Linux launcher entry:', e.message);