fix: full dosbox.conf with usescancodes=true + auto WASD for Doom

Root cause: Dosbox.conf was missing the [sdl] section with
'usescancodes=true' — without it DOSBox doesn't translate
keyboard scan codes and WASD keys don't register as game input.

Fix:
- Generate a complete dosbox.conf matching js-dos v8 standards
  (all sections: sdl, dosbox, cpu, mixer, render, midi,
   sblaster, gus, speaker, joystick, serial, dos, ipx, autoexec)
- Key setting: usescancodes=true + mapperfile=mapper-jsdos.map
- Uses svga_s3 machine type with SB16 audio (same as dos.zone)

Bonus: Auto-detect Doom-engine games (DOOM.WAD / DOOM2.WAD)
and inject a DEFAULT.CFG with WASD controls:
  W=forward, S=backward, A=strafe-left, D=strafe-right
  Arrows=turn, Ctrl=fire, Space=use, Alt=strafe, Shift=run
  Mouse enabled for looking

Note: Existing uploaded games still have the old dosbox.conf.
They need to be re-uploaded to get the fix.

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

@@ -83,11 +83,13 @@ public class UploadResource {
             if ("sockdrive".equals(bundleType)) {
                 // Copy files loose
                 copyDir(extractDir, gameDir);
-                // Write dosbox.conf
+                // Auto-inject WASD config for Doom-engine games
+                injectDoomConfig(extractDir, gameDir);
+                // Write dosbox.conf (full config, not just autoexec)
                 Path jsdos = gameDir.resolve(".jsdos");
                 Files.createDirectories(jsdos);
                 String relExe = Path.of(mainExe).getFileName().toString();
-                String conf = "[autoexec]\n@echo off\nmount c .\nc:\ncls\n" + relExe + "\n";
+                String conf = buildDosboxConf(relExe);
                 Files.writeString(jsdos.resolve("dosbox.conf"), conf);
                 bundleFile = ".jsdos/dosbox.conf";
             } else {
@@ -207,12 +209,14 @@ public class UploadResource {
         Path tmpBundle = Files.createTempDirectory("dostalgia-bundle-");
         try {
             copyDir(extractDir, tmpBundle);
+            // Auto-inject WASD config for Doom-engine games
+            injectDoomConfig(extractDir, tmpBundle);
 
-            // Create .jsdos config
+            // Create .jsdos config (full config, not just autoexec)
             Path jsdos = tmpBundle.resolve(".jsdos");
             Files.createDirectories(jsdos);
             String relExe = Path.of(mainExe).getFileName().toString();
-            String conf = "[autoexec]\n@echo off\nmount c .\nc:\ncls\n" + relExe + "\n";
+            String conf = buildDosboxConf(relExe);
             Files.writeString(jsdos.resolve("dosbox.conf"), conf);
 
             // ZIP it up
@@ -235,6 +239,176 @@ public class UploadResource {
 
     // ─── File Utilities ──────────────────────────────────────────
 
+    /**
+     * Build a complete dosbox.conf with all sections needed for proper
+     * keyboard and hardware emulation in js-dos v8.
+     */
+    private String buildDosboxConf(String relExe) {
+        return "[sdl]\n"
+            + "autolock=true\n"
+            + "fullscreen=false\n"
+            + "fulldouble=false\n"
+            + "fullresolution=original\n"
+            + "windowresolution=original\n"
+            + "output=surface\n"
+            + "sensitivity=100\n"
+            + "waitonerror=true\n"
+            + "priority=higher,normal\n"
+            + "mapperfile=mapper-jsdos.map\n"
+            + "usescancodes=true\n"
+            + "\n"
+            + "[dosbox]\n"
+            + "machine=svga_s3\n"
+            + "memsize=16\n"
+            + "\n"
+            + "[cpu]\n"
+            + "core=auto\n"
+            + "cputype=auto\n"
+            + "cycles=auto\n"
+            + "\n"
+            + "[mixer]\n"
+            + "nosound=false\n"
+            + "rate=44100\n"
+            + "blocksize=1024\n"
+            + "prebuffer=20\n"
+            + "\n"
+            + "[render]\n"
+            + "frameskip=0\n"
+            + "aspect=false\n"
+            + "scaler=none\n"
+            + "\n"
+            + "[midi]\n"
+            + "mpu401=intelligent\n"
+            + "mididevice=default\n"
+            + "midiconfig=\n"
+            + "\n"
+            + "[sblaster]\n"
+            + "sbtype=sb16\n"
+            + "sbbase=220\n"
+            + "irq=7\n"
+            + "dma=1\n"
+            + "hdma=5\n"
+            + "sbmixer=true\n"
+            + "oplmode=auto\n"
+            + "oplemu=default\n"
+            + "oplrate=44100\n"
+            + "\n"
+            + "[gus]\n"
+            + "gus=false\n"
+            + "gusrate=44100\n"
+            + "gusbase=240\n"
+            + "gusirq=5\n"
+            + "gusdma=3\n"
+            + "ultradir=C:\\ULTRASND\n"
+            + "\n"
+            + "[speaker]\n"
+            + "pcspeaker=true\n"
+            + "pcrate=44100\n"
+            + "tandy=auto\n"
+            + "tandyrate=44100\n"
+            + "disney=true\n"
+            + "\n"
+            + "[joystick]\n"
+            + "joysticktype=auto\n"
+            + "timed=true\n"
+            + "autofire=false\n"
+            + "swap34=false\n"
+            + "buttonwrap=false\n"
+            + "\n"
+            + "[serial]\n"
+            + "serial1=dummy\n"
+            + "serial2=dummy\n"
+            + "serial3=disabled\n"
+            + "serial4=disabled\n"
+            + "\n"
+            + "[dos]\n"
+            + "xms=true\n"
+            + "ems=true\n"
+            + "umb=true\n"
+            + "keyboardlayout=auto\n"
+            + "\n"
+            + "[ipx]\n"
+            + "ipx=true\n"
+            + "\n"
+            + "[autoexec]\n"
+            + "@echo off\n"
+            + "mount c .\n"
+            + "c:\n"
+            + "cls\n"
+            + relExe + "\n";
+    }
+
+    /**
+     * Detect Doom-engine games and inject a DEFAULT.CFG with WASD controls.
+     * Checks for DOOM.WAD or DOOM2.WAD in the source, then writes the
+     * config to the destination if it doesn't already have one.
+     */
+    private void injectDoomConfig(Path srcDir, Path dstDir) throws IOException {
+        boolean hasDoom = false;
+        try (var stream = Files.list(srcDir)) {
+            for (Path f : (Iterable<Path>) stream::iterator) {
+                String name = f.getFileName().toString().toUpperCase();
+                if (name.equals("DOOM.WAD") || name.equals("DOOM2.WAD")) {
+                    hasDoom = true;
+                    break;
+                }
+            }
+        }
+        if (!hasDoom) return;
+        // Don't overwrite an existing config
+        Path cfg = dstDir.resolve("DEFAULT.CFG");
+        if (Files.exists(cfg)) return;
+        Files.write(cfg, buildDoomDefaultCfg());
+        LOG.info("Doom detected — injected DEFAULT.CFG with WASD controls");
+    }
+
+    /**
+     * Build a DEFAULT.CFG (Doom engine config) with WASD controls.
+     * Only called when a DOOM.WAD or DOOM2.WAD is detected in the upload.
+     *
+     * Key bindings:
+     *   W=forward, S=backward, A=strafe left, D=strafe right
+     *   Arrows=turn, Ctrl=fire, Space=use, Alt=strafe, Shift=run
+     *   Mouse enabled for looking
+     */
+    private byte[] buildDoomDefaultCfg() {
+        String cfg = ""
+            + "mouse_sensitivity\t\t5\n"
+            + "sfx_volume\t\t8\n"
+            + "music_volume\t\t8\n"
+            + "show_messages\t\t1\n"
+            + "key_right\t\t77\n"        // Right arrow — turn right
+            + "key_left\t\t75\n"         // Left arrow  — turn left
+            + "key_up\t\t17\n"           // W — forward
+            + "key_down\t\t31\n"         // S — backward
+            + "key_strafeleft\t\t30\n"   // A — strafe left
+            + "key_straferight\t\t32\n"  // D — strafe right
+            + "key_fire\t\t29\n"         // Ctrl — fire
+            + "key_use\t\t57\n"          // Space — use/open
+            + "key_strafe\t\t56\n"       // Alt — strafe (hold)
+            + "key_speed\t\t54\n"        // Shift — run
+            + "use_mouse\t\t1\n"
+            + "mouseb_fire\t\t0\n"
+            + "mouseb_strafe\t\t1\n"
+            + "mouseb_forward\t\t2\n"
+            + "use_joystick\t\t0\n"
+            + "joyb_fire\t\t0\n"
+            + "joyb_strafe\t\t1\n"
+            + "joyb_use\t\t3\n"
+            + "joyb_speed\t\t2\n"
+            + "screenblocks\t\t10\n"
+            + "detaillevel\t\t0\n"
+            + "showmessages\t\t1\n"
+            + "comport\t\t1\n"
+            + "snd_channels\t\t3\n"
+            + "snd_musicdevice\t\t3\n"
+            + "snd_sfxdevice\t\t3\n"
+            + "snd_sbport\t\t544\n"
+            + "snd_sbirq\t\t7\n"
+            + "snd_sbdma\t\t1\n";
+        return cfg.getBytes(java.nio.charset.StandardCharsets.US_ASCII);
+    }
+
     private double dirSizeMB(Path dir) throws IOException {
         long[] total = {0};
         Files.walkFileTree(dir, new SimpleFileVisitor<>() {