Fix cross-platform duplicate .well-known path handling

Author: Piyush-t24

build.scala

@@ -86,8 +86,13 @@ object LaikaBuild {
     ).toURL()
 
     InputTree[IO]
+      // Exclude only the directory named .well-known when scanning parent dirs (e.g. src),
+      // so it is never included twice. We add it explicitly below so it appears on all platforms.
+      // (On Unix it's already skipped as hidden; on Windows it is included, causing duplicates.)
+      .withFileFilter(FileFilter.lift(_.name == ".well-known"))
       .addDirectory("src")
-      // Laika skips .dotfiles by default
+      // Laika skips .dotfiles by default (Unix); we add .well-known explicitly so
+      // it is included on all platforms at the correct virtual path.
       .addDirectory("src/.well-known", Path.Root / ".well-known")
       .addInputStream(
         IO.blocking(securityPolicy.openStream()),