WASM Python integration milestone - game.py runs in browser

Major milestone for issue #158 (Emscripten/WebAssembly build target):
- Python 3.14 successfully initializes and runs in WASM
- mcrfpy module loads and works correctly
- Game scripts execute with full level generation
- Entities (boulders, rats, cyclops, spawn points) placed correctly

Key changes:
- CMakeLists.txt: Add 2MB stack, Emscripten link options, preload files
- platform.h: Add WASM-specific implementations for executable paths
- HeadlessTypes.h: Make Texture/Font/Sound stubs return success
- CommandLineParser.cpp: Guard filesystem operations for WASM
- McRFPy_API.cpp: Add WASM path configuration, debug output
- game.py: Make 'code' module import optional (not available in WASM)
- wasm_stdlib/: Add minimal Python stdlib for WASM (~4MB)

Build with: emmake make (from build-emscripten/)
Test with: node mcrogueface.js

Next steps:
- Integrate VRSFML for actual WebGL rendering
- Create HTML page to host WASM build
- Test in actual browsers

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

wasm_stdlib/lib/python3.14/encodings/base64_codec.py

@@ -0,0 +1,55 @@
+"""Python 'base64_codec' Codec - base64 content transfer encoding.
+
+This codec de/encodes from bytes to bytes.
+
+Written by Marc-Andre Lemburg (mal@lemburg.com).
+"""
+
+import codecs
+import base64
+
+### Codec APIs
+
+def base64_encode(input, errors='strict'):
+    assert errors == 'strict'
+    return (base64.encodebytes(input), len(input))
+
+def base64_decode(input, errors='strict'):
+    assert errors == 'strict'
+    return (base64.decodebytes(input), len(input))
+
+class Codec(codecs.Codec):
+    def encode(self, input, errors='strict'):
+        return base64_encode(input, errors)
+    def decode(self, input, errors='strict'):
+        return base64_decode(input, errors)
+
+class IncrementalEncoder(codecs.IncrementalEncoder):
+    def encode(self, input, final=False):
+        assert self.errors == 'strict'
+        return base64.encodebytes(input)
+
+class IncrementalDecoder(codecs.IncrementalDecoder):
+    def decode(self, input, final=False):
+        assert self.errors == 'strict'
+        return base64.decodebytes(input)
+
+class StreamWriter(Codec, codecs.StreamWriter):
+    charbuffertype = bytes
+
+class StreamReader(Codec, codecs.StreamReader):
+    charbuffertype = bytes
+
+### encodings module API
+
+def getregentry():
+    return codecs.CodecInfo(
+        name='base64',
+        encode=base64_encode,
+        decode=base64_decode,
+        incrementalencoder=IncrementalEncoder,
+        incrementaldecoder=IncrementalDecoder,
+        streamwriter=StreamWriter,
+        streamreader=StreamReader,
+        _is_text_encoding=False,
+    )