fix(uc/qk): improve directory download with cookie, transfer fallback and URL-safe param encoding

- Preserve download cookie for UC/Quark needDownloader flows and disable browser/copy when required
- Quark: share-link first, transfer only on size limit (23018), reuse savedFileCache/search_exit
- Propagate auth to subdirectory parser URLs; switch path params to URL-safe Base64 (no double encode)
- Bump version to 0.4.2

Fixes #205

Co-authored-by: Cursor <cursoragent@cursor.com>

web-front/package.json

@@ -1,6 +1,6 @@
 {
   "name": "nfd-web",
-  "version": "0.4.1",
+  "version": "0.4.2",
   "private": true,
   "scripts": {
     "serve": "vue-cli-service serve",