fix: revert SKIP_EXT to original — exclude CD images from bundles

ORIGINAL SKIP_EXT (when games worked): excluded .img, .iso, .ccd,
.cue, .bin from bundles. My change included them, ballooning bundles
to hundreds of MB. The WASM libzip MEMFS can't handle such large
files → 'Unable to add .jsdos/jsdos.json into bundle.zip' + 'Not
a zip archive' on every game.

This is the ROOT CAUSE — confirmed by:
- Same error on ALL js-dos versions (8.3.14/emu-8.3.3 AND
  8.3.20/emu-8.3.8) → not a version issue
- Warcraft CD-ROM with CD images → HUGE bundle → fails
- Original code with SKIP_EXT excluding CD images → small
  bundles → works

Also reverted CD mounting logic in buildDosboxConf since there
are no CD images in the bundle to mount. CD image support will
be re-implemented separately via separate file serving.

src/main/java/com/dostalgia/GameService.java

@@ -168,7 +168,7 @@ public class GameService {
 
         // Build new config entries — preserve any CD images in the bundle
         List<String> cdImages = findCdImagesInBundle(bundlePath);
-        byte[] newDosboxConf = buildDosboxConfBytes(executable, cdImages);
+        byte[] newDosboxConf = buildDosboxConfBytes(executable);
         byte[] newJsdosJson = buildJsdosJsonBytes(executable);
 
         // Patch the ZIP: read old, write new with modified config entries
@@ -224,8 +224,8 @@ public class GameService {
         return cds;
     }
 
-    /** Build a dosbox.conf for a given executable path and optional CD images. */
-    private byte[] buildDosboxConfBytes(String relExe, List<String> cdImages) {
+    /** Build a dosbox.conf for a given executable path. */
+    private byte[] buildDosboxConfBytes(String relExe) {
         var parts = splitExePath(relExe);
         String dir = parts[0];
         String exe = parts[1];
@@ -236,31 +236,6 @@ public class GameService {
         sb.append("[sblaster]\nsbtype=sb16\nirq=7\ndma=1\nhdma=5\n\n");
         sb.append("[dos]\nxms=true\nems=true\numb=true\n\n");
         sb.append("[autoexec]\n@echo off\nmount c .\n");
-        // Mount CD images as D:, E:, … so games can find their CD.
-        // Deduplicate by parent directory — prefer data formats over descriptors.
-        Set<String> seenDirs = new java.util.HashSet<>();
-        char driveLetter = 'D';
-        for (String img : cdImages) {
-            int slashIdx = img.lastIndexOf('/');
-            String parentDir = slashIdx >= 0 ? img.substring(0, slashIdx) : "";
-            if (seenDirs.contains(parentDir)) continue;
-            String imgLower = img.toLowerCase();
-            // Skip descriptor formats if a data format exists in the same directory
-            if (imgLower.endsWith(".cue") || imgLower.endsWith(".ccd")) {
-                boolean hasData = cdImages.stream().anyMatch(i -> {
-                    int is = i.lastIndexOf('/');
-                    String ip = is >= 0 ? i.substring(0, is) : "";
-                    String il = i.toLowerCase();
-                    return ip.equals(parentDir)
-                        && (il.endsWith(".img") || il.endsWith(".iso") || il.endsWith(".bin"));
-                });
-                if (hasData) continue;
-            }
-            seenDirs.add(parentDir);
-            String flags = imgLower.endsWith(".bin") ? " -t cdrom -fs iso" : " -t cdrom";
-            sb.append("imgmount ").append(driveLetter).append(" \"").append(img).append("\"").append(flags).append("\n");
-            driveLetter++;
-        }
         sb.append("c:\n");
         if (dir != null) {
             sb.append("path=c:\\\n");
@@ -365,7 +340,7 @@ public class GameService {
 
         // Build new config entries — preserve any CD images in the bundle
         List<String> cdImages = findCdImagesInBundle(bundlePath);
-        byte[] newDosboxConf = buildDosboxConfBytes(setupExe, cdImages);
+        byte[] newDosboxConf = buildDosboxConfBytes(setupExe);
         byte[] newJsdosJson = buildJsdosJsonBytes(setupExe);
 
         try (var zis = new java.util.zip.ZipInputStream(Files.newInputStream(bundlePath));
@@ -401,7 +376,7 @@ public class GameService {
         byte[] dosboxConf;
         byte[] jsdosConf;
         if (exe != null && !exe.isBlank()) {
-            dosboxConf = buildDosboxConfBytes(exe, cdImages);
+            dosboxConf = buildDosboxConfBytes(exe);
             jsdosConf = buildJsdosJsonBytes(exe);
         } else {
             // CD-only game — generate CD-only config

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

@@ -397,13 +397,11 @@ public class UploadResource {
 
     // ─── Bundle Creation ─────────────────────────────────────────
 
-    /** File extensions that are never game data and should be excluded from .jsdos bundles.
-     *  Only formats DOSBox can't mount natively are stripped.
-     *  Mountable formats (.iso, .cue, .img, .ccd) are kept and auto-mounted via imgmount. */
+    /** File extensions that are never game data and should be excluded from .jsdos bundles. */
     private static final java.util.Set<String> SKIP_EXT = java.util.Set.of(
-        ".nrg", ".mdf", ".mds",  // disk images DOSBox can't mount natively
-        ".sub",                  // subchannel data (accompanies .ccd — CCD itself is kept)
-        ".dmg"                   // Mac disk images
+        ".img", ".iso", ".nrg", ".mdf", ".mds",  // disk images
+        ".ccd", ".sub", ".cue", ".bin",          // CloneCD / CUE sheets + binaries
+        ".dmg"                                     // Mac disk images
     );
 
     /** File extensions that DOSBox can mount as CD-ROM via imgmount. */
@@ -517,7 +515,7 @@ public class UploadResource {
         Files.createDirectories(jsdos);
         if (exePath != null) {
             String relExe = extractDir.relativize(Path.of(exePath)).toString();
-            Files.writeString(jsdos.resolve("dosbox.conf"), buildDosboxConf(relExe, cdImages));
+            Files.writeString(jsdos.resolve("dosbox.conf"), buildDosboxConf(relExe));
             Files.write(jsdos.resolve("jsdos.json"), buildJsdosJson(relExe));
         } else {
             // CD-only game — no executable, mount CD and show a DOS prompt
@@ -709,7 +707,7 @@ public class UploadResource {
         return json.getBytes(java.nio.charset.StandardCharsets.UTF_8);
     }
 
-    private String buildDosboxConf(String relExe, List<String> cdImages) {
+    private String buildDosboxConf(String relExe) {
         // DOS uses \\ as path separator; / is a switch character.
         // If the executable is in a subdirectory, cd into it first.
         var parts = splitDirExe(relExe);
@@ -743,16 +741,6 @@ public class UploadResource {
         sb.append("[autoexec]\n");
         sb.append("@echo off\n");
         sb.append("mount c .\n");
-        // Mount CD images as D:, E:, … so games can find their CD.
-        // Resolve one image per directory with format priority (.cue > .iso > .ccd > .img > .bin)
-        char driveLetter = 'D';
-        for (String img : resolveCdImages(cdImages)) {
-            String imgLower = img.toLowerCase();
-            String flags = (imgLower.endsWith(".bin") && !imgLower.endsWith(".cue"))
-                ? " -t cdrom -fs iso" : " -t cdrom";
-            sb.append("imgmount ").append(driveLetter).append(" \"").append(img).append("\"").append(flags).append("\n");
-            driveLetter++;
-        }
         sb.append("c:\n");
         if (dir != null) {
             sb.append("path=c:\\\n");