fix: report per-file progress while downloading Mojang Java

MojangJavaDownloadTask never called updateProgress, so its progress bar stayed
indeterminate while the hidden LZMA-decompress and cache-copy steps wrote files
to disk. Players saw 0KB speed and a frozen-looking bar and restarted the
launcher. Append a progress callback after each file completes so the bar
advances through download/decompress/copy phases; the download logic is unchanged.

HMCLCore/src/main/java/org/jackhuang/hmcl/download/java/mojang/MojangJavaDownloadTask.java

@@ -25,6 +25,7 @@ import java.nio.file.attribute.BasicFileAttributes;
 import java.security.DigestInputStream;
 import java.security.MessageDigest;
 import java.util.*;
+import java.util.concurrent.atomic.AtomicInteger;
 
 import static org.jackhuang.hmcl.util.logging.Logger.LOG;
 
@@ -37,6 +38,8 @@ public final class MojangJavaDownloadTask extends Task<MojangJavaDownloadTask.Re
     private final Path tempDir;
     private final Task<MojangJavaRemoteFiles> javaDownloadsTask;
     private final List<Task<?>> dependencies = new ArrayList<>();
+    private final AtomicInteger completedFiles = new AtomicInteger();
+    private volatile int totalFiles;
 
     private volatile MojangJavaDownloads.JavaDownload download;
 
@@ -147,6 +150,21 @@ public final class MojangJavaDownloadTask extends Task<MojangJavaDownloadTask.Re
                 Files.createSymbolicLink(dest, Paths.get(link.getTarget()));
             }
         }
+
+        // Report per-file progress so the bar advances through the download, LZMA decompress and
+        // cache-copy phases; otherwise it stays indeterminate while files appear on disk and players
+        // assume the install is frozen. The callbacks run after each file completes and never touch
+        // the download/decompress logic above.
+        totalFiles = dependencies.size();
+        if (totalFiles > 0) {
+            List<Task<?>> tracked = new ArrayList<>(totalFiles);
+            for (Task<?> dependency : dependencies) {
+                tracked.add(dependency.thenRunAsync(() -> updateProgress(completedFiles.incrementAndGet(), totalFiles)));
+            }
+            dependencies.clear();
+            dependencies.addAll(tracked);
+            updateProgress(0, totalFiles);
+        }
     }
 
     @Override