feat: implement backup system with compression and bundling

- Add zstd-jni dependency for compression support
- Define Backup record with name, key, incremental, and size fields
- Implement BackupManager with backup listing, deletion, and creation methods
- Create BackupWorker to handle backup operations with server state coordination
- Refactor WorldDir to simplify dimension handling and file listing
- Introduce bundling system with SerialBundlerReader^[[1;5P/Writer for efficient storage
- Add BackupStrategy interface with LocalBackupStrategy implementation
- Support both compressed and uncompressed backup formats
- Add config option for parallel backup operations
- Remove old backup implementation from JustBackupMod
- Update backup file format with metadata footer and magic number validation

src/main/java/io/ib67/sfcraft/bundler/EntryOutputStream.java

@@ -0,0 +1,37 @@
+package io.ib67.sfcraft.bundler;
+
+import java.io.FilterOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+
+public class EntryOutputStream extends FilterOutputStream {
+    /**
+     * Creates an output stream filter built on top of the specified
+     * underlying output stream.
+     *
+     * @param out the underlying output stream to be assigned to
+     *            the field {@code this.out} for later use, or
+     *            {@code null} if this instance is to be
+     *            created without an underlying stream.
+     */
+    public EntryOutputStream(OutputStream out) {
+        super(out);
+    }
+
+    public void writeMagic() throws IOException {
+        out.write(BundlerEntry.MAGIC);
+    }
+
+    public void write(BundlerEntry entry) throws IOException {
+        var fileName = entry.fileName().getBytes(StandardCharsets.UTF_8);
+        var buf = ByteBuffer.allocate(4).putInt(entry.unGzipped() ? fileName.length * -1 : fileName.length);
+        out.write(buf.array());
+        out.write(fileName);
+        buf = ByteBuffer.allocate(8 + 8);
+        buf.putLong(entry.fileLength());
+        buf.putLong(entry.offset());
+        out.write(buf.array());
+    }
+}