feat: fix hardcoded DOS paths in configs during upload + fix-paths endpoint

- Add both uppercase C: and lowercase c: variants to CONFIG_PATH_FIXES
- Add fixBundleConfigPaths() to GameService to patch existing bundles
- Add POST /api/games/{id}/fix-paths endpoint for existing games

src/main/java/com/dostalgia/GameResource.java

@@ -164,6 +164,25 @@ public class GameResource {
         }
     }
 
+    @POST
+    @Path("/{id}/fix-paths")
+    @Produces(MediaType.APPLICATION_JSON)
+    public Response fixPaths(@PathParam("id") String id) {
+        try {
+            boolean patched = svc.fixBundleConfigPaths(id);
+            if (patched) {
+                return Response.ok(Map.of("status", "patched",
+                    "message", "Fixed hardcoded DOS paths in game config")).build();
+            }
+            return Response.ok(Map.of("status", "noop",
+                "message", "No known config files needed patching")).build();
+        } catch (NoSuchFileException e) {
+            return Response.status(404).entity(Map.of("error", "Game not found")).build();
+        } catch (Exception e) {
+            return Response.serverError().entity(Map.of("error", e.getMessage())).build();
+        }
+    }
+
     private Integer asInt(Object v) {
         if (v instanceof Number n) return n.intValue();
         return null;

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

@@ -204,6 +204,97 @@ public class GameService {
         save(game);
     }
 
+    /**
+     * Known game config files with hardcoded DOS paths that need fixing.
+     * Same as UploadResource.CONFIG_PATH_FIXES but duplicated here for
+     * the fix-paths endpoint (no dependency on UploadResource).
+     */
+    private static final java.util.Map<String, java.util.List<String>> CONFIG_PATH_FIXES =
+        java.util.Map.of(
+            "fallout.cfg", java.util.List.of(
+                "c:\\fallout1\\", "C:\\fallout1\\",
+                "c:\\fallout2\\", "C:\\fallout2\\",
+                "c:\\fallout\\",  "C:\\fallout\\"
+            )
+        );
+
+    /** Patch hardcoded DOS paths (C:\dir\ → .\) in known game config files within a .jsdos bundle. */
+    public boolean fixBundleConfigPaths(String id) throws IOException {
+        Game game = load(id);
+        String bundleFile = game.getBundleFile();
+        if (bundleFile == null) return false;
+        Path bundlePath = gamesDir.resolve(bundleFile);
+        if (!Files.exists(bundlePath)) return false;
+
+        Path tmpPath = bundlePath.resolveSibling(bundlePath.getFileName() + ".tmp");
+        boolean patched = false;
+
+        try (var zis = new java.util.zip.ZipInputStream(Files.newInputStream(bundlePath));
+             var zos = new java.util.zip.ZipOutputStream(Files.newOutputStream(tmpPath))) {
+
+            java.util.zip.ZipEntry entry;
+            while ((entry = zis.getNextEntry()) != null) {
+                String name = entry.getName();
+                String loName = name.toLowerCase();
+                var prefixes = CONFIG_PATH_FIXES.get(loName);
+                zos.putNextEntry(new java.util.zip.ZipEntry(name));
+
+                if (prefixes != null) {
+                    // Read the entry content and patch paths
+                    byte[] data = zis.readAllBytes();
+                    byte[] result = data;
+                    for (String prefix : prefixes) {
+                        byte[] pBytes = prefix.getBytes(java.nio.charset.StandardCharsets.ISO_8859_1);
+                        byte[] pSlash = prefix.replace('\\', '/')
+                            .getBytes(java.nio.charset.StandardCharsets.ISO_8859_1);
+                        byte[] rel = ".\\".getBytes(java.nio.charset.StandardCharsets.ISO_8859_1);
+                        byte[] relSlash = "./"
+                            .getBytes(java.nio.charset.StandardCharsets.ISO_8859_1);
+                        result = replaceBytesInPlace(result, pBytes, rel);
+                        result = replaceBytesInPlace(result, pSlash, relSlash);
+                    }
+                    if (!java.util.Arrays.equals(result, data)) {
+                        patched = true;
+                    }
+                    zos.write(result);
+                } else {
+                    zis.transferTo(zos);
+                }
+                zos.closeEntry();
+                zis.closeEntry();
+            }
+        }
+
+        if (patched) {
+            Files.move(tmpPath, bundlePath, StandardCopyOption.REPLACE_EXISTING);
+        } else {
+            Files.deleteIfExists(tmpPath);
+        }
+        return patched;
+    }
+
+    private static byte[] replaceBytesInPlace(byte[] src, byte[] search, byte[] replacement) {
+        if (search.length == 0) return src;
+        java.util.ArrayList<Byte> result = new java.util.ArrayList<>(src.length);
+        int i = 0;
+        while (i <= src.length - search.length) {
+            boolean match = true;
+            for (int j = 0; j < search.length; j++) {
+                if (src[i + j] != search[j]) { match = false; break; }
+            }
+            if (match) {
+                for (byte b : replacement) result.add(b);
+                i += search.length;
+            } else {
+                result.add(src[i++]);
+            }
+        }
+        while (i < src.length) result.add(src[i++]);
+        byte[] out = new byte[result.size()];
+        for (int k = 0; k < out.length; k++) out[k] = result.get(k);
+        return out;
+    }
+
     /** Scan a .jsdos bundle for CD image files (preserves the case from the ZIP entry). */
     private List<String> findCdImagesInBundle(Path bundlePath) throws IOException {
         Set<String> cdExt = Set.of(".iso", ".cue", ".img", ".ccd", ".bin");

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

@@ -485,7 +485,11 @@ public class UploadResource {
      *  replace with ".\\" (relative to the game root). */
     private static final java.util.Map<String, java.util.List<String>> CONFIG_PATH_FIXES =
         java.util.Map.of(
-            "fallout.cfg", java.util.List.of("c:\\fallout1\\", "c:\\fallout2\\", "c:\\fallout\\")
+            "fallout.cfg", java.util.List.of(
+                "c:\\fallout1\\", "C:\\fallout1\\",
+                "c:\\fallout2\\", "C:\\fallout2\\",
+                "c:\\fallout\\",  "C:\\fallout\\"
+            )
         );
 
     /**