Fix ZIP entry order: write .jsdos/ config first, then game files sorted

js-dos reads ZIP entries sequentially and needs .jsdos/dosbox.conf and
.jsdos/jsdos.json first to configure DOSBox. Java's Files.walk() uses
filesystem readdir order which put them at the very end of the ZIP
(after the 328MB CloneCD image), causing extraction failures.

Now:
1. First pass: walk .jsdos/ directory and write config files first
2. Second pass: walk everything else (excluding .jsdos/) in sorted order
3. All directory ancestors are still added as explicit entries
4. .sorted() ensures deterministic, alphabetical entry order

src/main/java/com/dostalgia/UploadResource.java

@@ -290,27 +290,52 @@ public class UploadResource {
         // ZIP it up directly from extractDir (no temp copy)
         try (var zos = new java.util.zip.ZipOutputStream(Files.newOutputStream(bundlePath))) {
             var addedDirs = new java.util.HashSet<String>();
-            Files.walk(extractDir).filter(Files::isRegularFile).forEach(f -> {
-                try {
-                    String entryName = extractDir.relativize(f).toString().replace('\\', '/');
-                    // Ensure ALL ancestor directories have explicit entries
-                    // (Emscripten FS requires every directory in the chain)
+
+            // Helper: write a directory entry and all its ancestors if not yet added
+            // (Emscripten FS requires every directory in the chain as explicit entries)
+            java.util.function.Consumer<String> ensureDir = entryName -> {
                 int idx = entryName.lastIndexOf('/');
                 while (idx >= 0) {
                     String parent = entryName.substring(0, idx + 1);
                     if (addedDirs.add(parent)) {
+                        try {
                             zos.putNextEntry(new java.util.zip.ZipEntry(parent));
                             zos.closeEntry();
+                        } catch (IOException e) {
+                            throw new UncheckedIOException(e);
+                        }
                     }
                     idx = entryName.lastIndexOf('/', idx - 1);
                 }
+            };
+
+            // Helper: write a single file entry with its directory chain
+            java.util.function.Consumer<Path> writeFile = f -> {
+                try {
+                    String entryName = extractDir.relativize(f).toString().replace('\\', '/');
+                    ensureDir.accept(entryName);
                     zos.putNextEntry(new java.util.zip.ZipEntry(entryName));
                     Files.copy(f, zos);
                     zos.closeEntry();
                 } catch (IOException e) {
                     throw new UncheckedIOException(e);
                 }
-            });
+            };
+
+            // ── First pass: .jsdos config files (must come first in ZIP) ──
+            try (var walk = Files.walk(jsdos)) {
+                walk.filter(Files::isRegularFile)
+                    .sorted() // deterministic order
+                    .forEach(writeFile);
+            }
+
+            // ── Second pass: all other game files ──
+            try (var walk = Files.walk(extractDir)) {
+                walk.filter(Files::isRegularFile)
+                    .filter(f -> !f.startsWith(jsdos))
+                    .sorted() // deterministic order
+                    .forEach(writeFile);
+            }
         }
 
         // Clean up .jsdos config files from the extract dir