fix(electron): properly dereference symlinks by copying actual content (#610)

cpSync with dereference:true does NOT convert symlinks to files.
This implements a custom copyDereferenced function that:
- Detects symlinks using lstatSync
- Follows them using statSync
- Copies actual file/directory content instead of symlink

Fixes macOS arm64 codesign failure with electron-builder 26.4.0
which now does ad-hoc signing and runs codesign --verify.

scripts/afterPack.cjs

@@ -3,9 +3,49 @@
  * Copies node_modules to the standalone directory in the packaged app
  */
 
-const { cpSync, existsSync } = require("fs")
+const {
+    copyFileSync,
+    existsSync,
+    lstatSync,
+    mkdirSync,
+    readdirSync,
+    statSync,
+} = require("fs")
 const path = require("path")
 
+/**
+ * Copy directory recursively, converting symlinks to regular files/directories.
+ * This is needed because cpSync with dereference:true does NOT convert symlinks.
+ * macOS codesign fails if bundle contains symlinks pointing outside the bundle.
+ */
+function copyDereferenced(src, dst) {
+    const lstat = lstatSync(src)
+
+    if (lstat.isSymbolicLink()) {
+        // Follow symlink and check what it points to
+        const stat = statSync(src)
+        if (stat.isDirectory()) {
+            // Symlink to directory: recursively copy the directory contents
+            mkdirSync(dst, { recursive: true })
+            for (const entry of readdirSync(src)) {
+                copyDereferenced(path.join(src, entry), path.join(dst, entry))
+            }
+        } else {
+            // Symlink to file: copy the actual file content
+            mkdirSync(path.join(dst, ".."), { recursive: true })
+            copyFileSync(src, dst)
+        }
+    } else if (lstat.isDirectory()) {
+        mkdirSync(dst, { recursive: true })
+        for (const entry of readdirSync(src)) {
+            copyDereferenced(path.join(src, entry), path.join(dst, entry))
+        }
+    } else {
+        mkdirSync(path.join(dst, ".."), { recursive: true })
+        copyFileSync(src, dst)
+    }
+}
+
 module.exports = async (context) => {
     const appOutDir = context.appOutDir
     const resourcesDir = path.join(
@@ -25,10 +65,7 @@ module.exports = async (context) => {
     console.log(`[afterPack] Copying node_modules to ${targetNodeModules}`)
 
     if (existsSync(sourceNodeModules) && existsSync(standaloneDir)) {
-        cpSync(sourceNodeModules, targetNodeModules, {
-            recursive: true,
-            dereference: true,
-        })
+        copyDereferenced(sourceNodeModules, targetNodeModules)
         console.log("[afterPack] node_modules copied successfully")
     } else {
         console.error("[afterPack] Source or target directory not found!")