Fix trailing slash in VFOX_NODEJS_MIRROR causing double slashes in URL paths (#25)

* Initial plan

* Fix trailing slash issue in VFOX_NODEJS_MIRROR URL handling

Co-authored-by: bytemain <13938334+bytemain@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: bytemain <13938334+bytemain@users.noreply.github.com>

Author: Copilot

README.md

@@ -13,4 +13,5 @@ vfox add nodejs
 ## Mirror
 
 You can configure the mirror by `VFOX_NODEJS_MIRROR` environment variable. The default value
-is `https://nodejs.org/dist/`.
+is `https://nodejs.org/dist`. Trailing slashes are automatically handled, so both
+`https://nodejs.org/dist` and `https://nodejs.org/dist/` will work correctly.

lib/util.lua

@@ -9,7 +9,8 @@ function UTIL.getBaseUrl()
     if mirror == "" or mirror == nil then
         return "https://nodejs.org/dist"
     end
-    return mirror
+    -- Strip trailing slash to avoid double slashes in URL paths
+    return mirror:gsub("/$", "")
 end
 
 function UTIL.compare_versions(v1o, v2o)