Number output files and folders instead of overwriting

Pack now writes <Name>.cache, or <Name>.cache.1, .2, ... if that file
already exists (replaces the fixed .cache.new name). Unpack writes each
target folder under ARCANE_DUMP the same way, e.g. COBJECTS.1. The
output folder is created only after the cache loads, so a missing cache
does not leave an empty numbered folder.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

mbEditorPro2.0/arcane/util/ArcFileCache.py

@@ -6,6 +6,7 @@
 #                Magicbane Emulator Project © 2013 - 2022
 #                           www.magicbane.com
 
+import os
 import struct
 import zlib
 
@@ -81,7 +82,21 @@ def write_bytes(cache_file, value):
     cache_file.write(value)
 
 
+def next_available_path(path):
+    # Returns path if unused, otherwise the first free path.1, path.2, ...
+    if not os.path.exists(path):
+        return path
+
+    index = 1
+    while os.path.exists(f'{path}.{index}'):
+        index += 1
+
+    return f'{path}.{index}'
+
+
 def save_cache_file(filename, resources, compress=True):
+    filename = next_available_path(filename)
+    print('Packing to ' + filename)
     cache_file = open(filename, 'wb')
 
     num_resources = len(resources)