fix dll overrides & add disable UMU

src/importer.js

@@ -1,6 +1,7 @@
 'use strict'
 
-const fsp = require('fs').promises
+const fs = require('fs')
+const fsp = fs.promises
 const path = require('path')
 const { DIRS, resolvePortablePath } = require('./paths')
 const { newGame, newGameId, addGame } = require('./library')
@@ -82,8 +83,22 @@ async function importGameFromPrefix(prefix, srcDir, onProgress) {
   const driveRoots = prefixDriveRoots(prefix)
   if (!driveRoots.length) return { ok: false, error: 'no-drive-c' }
   const src = path.resolve(String(srcDir))
+  // realpath on both sides: a unified prefix reaches drive_c through the pfx
+  // symlink too, and that path is the same folder (see ensureUnifiedPrefix)
+  let realSrc
+  try {
+    realSrc = fs.realpathSync(src)
+  } catch {
+    return { ok: false, error: 'outside-drive-c' }
+  }
   const insideDrive = driveRoots.some(root => {
-    const rel = path.relative(root, src)
+    let realRoot
+    try {
+      realRoot = fs.realpathSync(root)
+    } catch {
+      return false
+    }
+    const rel = path.relative(realRoot, realSrc)
     return rel && !rel.startsWith('..') && !path.isAbsolute(rel)
   })
   if (!insideDrive) return { ok: false, error: 'outside-drive-c' }