Fix Play button 404: bundle path and field name

- .jsdos bundles saved flat in data/games/ so /games/{id}.jsdos serves them
- bundleUrl() uses game.id (matches JSON) instead of game.slug (undefined)
- Delete handler also removes flat .jsdos bundle on game deletion

upload.go

@@ -126,9 +126,9 @@ func handleUploadGame(w http.ResponseWriter, r *http.Request) {
 			[]byte(fmt.Sprintf(dosboxConfTemplate, relExe)), 0644)
 		bundleFile = ".jsdos/dosbox.conf"
 	} else {
-		// Create .jsdos ZIP bundle
+		// Create .jsdos ZIP bundle flat in data/games/
 		bundleFile = gameID + ".jsdos"
-		bundlePath := filepath.Join(gameDirPath, bundleFile)
+		bundlePath := filepath.Join(filepath.Dir(gameDirPath), bundleFile)
 		if err := createJSDOSBundle(extractDir, mainExe, bundlePath); err != nil {
 			http.Error(w, "Failed to create bundle: "+err.Error(), http.StatusInternalServerError)
 			return