feat(FN-1074): add desktop tray and application menu

- Add dedicated desktop tray and menu modules, including platform-aware menu templates and tray status/visibility controls
- Integrate tray setup, app menu initialization, and tray status exports into the Electron main process bootstrap
- Add tray icon assets plus an icon generation script and update desktop package dependencies/lockfile
- Expand desktop test coverage with new menu/tray test suites and main process integration assertions
- Update desktop README with tray and application menu usage/documentation

packages/desktop/scripts/generate-icons.ts

@@ -0,0 +1,34 @@
+import { mkdir, readFile } from "node:fs/promises";
+import { dirname, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+import sharp from "sharp";
+
+const scriptDir = dirname(fileURLToPath(import.meta.url));
+const packageDir = resolve(scriptDir, "..");
+const repoRoot = resolve(packageDir, "../..");
+
+const sourceSvgPath = resolve(repoRoot, "packages/dashboard/app/public/logo.svg");
+const outputDir = resolve(packageDir, "src/icons");
+
+const iconSizes = [16, 32, 48] as const;
+
+async function main(): Promise<void> {
+  const sourceSvg = await readFile(sourceSvgPath, "utf8");
+  const tintedSvg = sourceSvg.replaceAll("currentColor", "#333333");
+
+  await mkdir(outputDir, { recursive: true });
+
+  await Promise.all(
+    iconSizes.map(async (size) => {
+      const outputPath = resolve(outputDir, `tray-${size}.png`);
+      await sharp(Buffer.from(tintedSvg), { density: 1024 })
+        .resize(size, size, { fit: "contain" })
+        .png({ compressionLevel: 9 })
+        .toFile(outputPath);
+    }),
+  );
+
+  console.log(`Generated ${iconSizes.length} tray icons in ${outputDir}`);
+}
+
+void main();