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/struct.py

@@ -0,0 +1,15 @@
+__all__ = [
+    # Functions
+    'calcsize', 'pack', 'pack_into', 'unpack', 'unpack_from',
+    'iter_unpack',
+
+    # Classes
+    'Struct',
+
+    # Exceptions
+    'error'
+    ]
+
+from _struct import *
+from _struct import _clearcache  # noqa: F401
+from _struct import __doc__  # noqa: F401