fix(electron): stage standalone bundle for desktop builds

Prepare a dedicated `.next/electron-standalone` bundle before
running electron-builder so desktop packaging operates on a stable,
Electron-specific server payload.

This also adds a preflight that rejects standalone bundles whose
top-level `node_modules` is a symlink, because electron-builder
preserves `extraResources` symlinks and would otherwise ship an app
that depends on the build machine at runtime.

scripts/prepare-electron-standalone.mjs

@@ -0,0 +1,136 @@
+#!/usr/bin/env node
+
+import {
+  cpSync,
+  existsSync,
+  lstatSync,
+  mkdirSync,
+  readFileSync,
+  rmSync,
+  writeFileSync,
+} from "node:fs";
+import { dirname, join, relative } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+const ROOT = join(__dirname, "..");
+
+const STANDALONE_DIR = join(ROOT, ".next", "standalone");
+const ELECTRON_STANDALONE_DIR = join(ROOT, ".next", "electron-standalone");
+const STATIC_SRC = join(ROOT, ".next", "static");
+const STATIC_DEST = join(ELECTRON_STANDALONE_DIR, ".next", "static");
+const PUBLIC_SRC = join(ROOT, "public");
+const PUBLIC_DEST = join(ELECTRON_STANDALONE_DIR, "public");
+
+function resolveStandaloneBundleDir() {
+  const directServer = join(STANDALONE_DIR, "server.js");
+  if (existsSync(directServer)) {
+    return STANDALONE_DIR;
+  }
+
+  const nestedCandidates = [
+    join(STANDALONE_DIR, "projects", "OmniRoute"),
+    join(STANDALONE_DIR, basename(ROOT)),
+  ];
+
+  for (const candidate of nestedCandidates) {
+    if (existsSync(join(candidate, "server.js"))) {
+      return candidate;
+    }
+  }
+
+  throw new Error(
+    `Standalone server bundle not found in ${STANDALONE_DIR}. Run \`npm run build\` first.`
+  );
+}
+
+function basename(filePath) {
+  return filePath.split(/[\\/]/).filter(Boolean).at(-1) || filePath;
+}
+
+function sanitizeBuildPaths(bundleDir) {
+  const buildRoot = ROOT.replace(/\\/g, "/");
+  const bundleRoot = bundleDir.replace(/\\/g, "/");
+  const replacements = [buildRoot, bundleRoot];
+  const targets = [
+    join(ELECTRON_STANDALONE_DIR, "server.js"),
+    join(ELECTRON_STANDALONE_DIR, ".next", "required-server-files.json"),
+  ];
+
+  for (const filePath of targets) {
+    if (!existsSync(filePath)) continue;
+
+    let content = readFileSync(filePath, "utf8");
+    let updated = content;
+
+    for (const original of replacements) {
+      const escaped = original.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+      updated = updated.replace(new RegExp(escaped, "g"), ".");
+    }
+
+    if (updated !== content) {
+      writeFileSync(filePath, updated, "utf8");
+    }
+  }
+}
+
+function ensurePackage(pkgPath, sourcePath) {
+  if (existsSync(pkgPath) || !existsSync(sourcePath)) return;
+  mkdirSync(dirname(pkgPath), { recursive: true });
+  cpSync(sourcePath, pkgPath, { recursive: true, dereference: true });
+}
+
+function assertBundleIsPackagable(bundleDir) {
+  const nodeModulesPath = join(bundleDir, "node_modules");
+  if (!existsSync(nodeModulesPath)) return;
+
+  if (lstatSync(nodeModulesPath).isSymbolicLink()) {
+    throw new Error(
+      [
+        "Next standalone emitted app/node_modules as a symlink.",
+        "electron-builder preserves extraResources symlinks, which would make the packaged app",
+        "depend on the original build machine path at runtime.",
+        "",
+        `Offending path: ${nodeModulesPath}`,
+        "Use a real node_modules directory in the build worktree before packaging Electron.",
+      ].join("\n")
+    );
+  }
+}
+
+const bundleDir = resolveStandaloneBundleDir();
+assertBundleIsPackagable(bundleDir);
+
+rmSync(ELECTRON_STANDALONE_DIR, { recursive: true, force: true });
+mkdirSync(ELECTRON_STANDALONE_DIR, { recursive: true });
+
+cpSync(bundleDir, ELECTRON_STANDALONE_DIR, {
+  recursive: true,
+  dereference: true,
+});
+
+sanitizeBuildPaths(bundleDir);
+
+if (existsSync(STATIC_SRC)) {
+  mkdirSync(dirname(STATIC_DEST), { recursive: true });
+  cpSync(STATIC_SRC, STATIC_DEST, { recursive: true, dereference: true });
+}
+
+if (existsSync(PUBLIC_SRC)) {
+  cpSync(PUBLIC_SRC, PUBLIC_DEST, { recursive: true, dereference: true });
+}
+
+ensurePackage(
+  join(ELECTRON_STANDALONE_DIR, "node_modules", "@swc", "helpers"),
+  join(ROOT, "node_modules", "@swc", "helpers")
+);
+
+ensurePackage(
+  join(ELECTRON_STANDALONE_DIR, "node_modules", "better-sqlite3"),
+  join(ROOT, "node_modules", "better-sqlite3")
+);
+
+console.log(
+  `[electron] prepared standalone bundle: ${relative(ROOT, ELECTRON_STANDALONE_DIR) || "."}`
+);