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/_weakrefset.py

@@ -0,0 +1,147 @@
+# Access WeakSet through the weakref module.
+# This code is separated-out because it is needed
+# by abc.py to load everything else at startup.
+
+from _weakref import ref
+from types import GenericAlias
+
+__all__ = ['WeakSet']
+
+
+class WeakSet:
+    def __init__(self, data=None):
+        self.data = set()
+
+        def _remove(item, selfref=ref(self)):
+            self = selfref()
+            if self is not None:
+                self.data.discard(item)
+
+        self._remove = _remove
+        if data is not None:
+            self.update(data)
+
+    def __iter__(self):
+        for itemref in self.data.copy():
+            item = itemref()
+            if item is not None:
+                # Caveat: the iterator will keep a strong reference to
+                # `item` until it is resumed or closed.
+                yield item
+
+    def __len__(self):
+        return len(self.data)
+
+    def __contains__(self, item):
+        try:
+            wr = ref(item)
+        except TypeError:
+            return False
+        return wr in self.data
+
+    def __reduce__(self):
+        return self.__class__, (list(self),), self.__getstate__()
+
+    def add(self, item):
+        self.data.add(ref(item, self._remove))
+
+    def clear(self):
+        self.data.clear()
+
+    def copy(self):
+        return self.__class__(self)
+
+    def pop(self):
+        while True:
+            try:
+                itemref = self.data.pop()
+            except KeyError:
+                raise KeyError('pop from empty WeakSet') from None
+            item = itemref()
+            if item is not None:
+                return item
+
+    def remove(self, item):
+        self.data.remove(ref(item))
+
+    def discard(self, item):
+        self.data.discard(ref(item))
+
+    def update(self, other):
+        for element in other:
+            self.add(element)
+
+    def __ior__(self, other):
+        self.update(other)
+        return self
+
+    def difference(self, other):
+        newset = self.copy()
+        newset.difference_update(other)
+        return newset
+    __sub__ = difference
+
+    def difference_update(self, other):
+        self.__isub__(other)
+    def __isub__(self, other):
+        if self is other:
+            self.data.clear()
+        else:
+            self.data.difference_update(ref(item) for item in other)
+        return self
+
+    def intersection(self, other):
+        return self.__class__(item for item in other if item in self)
+    __and__ = intersection
+
+    def intersection_update(self, other):
+        self.__iand__(other)
+    def __iand__(self, other):
+        self.data.intersection_update(ref(item) for item in other)
+        return self
+
+    def issubset(self, other):
+        return self.data.issubset(ref(item) for item in other)
+    __le__ = issubset
+
+    def __lt__(self, other):
+        return self.data < set(map(ref, other))
+
+    def issuperset(self, other):
+        return self.data.issuperset(ref(item) for item in other)
+    __ge__ = issuperset
+
+    def __gt__(self, other):
+        return self.data > set(map(ref, other))
+
+    def __eq__(self, other):
+        if not isinstance(other, self.__class__):
+            return NotImplemented
+        return self.data == set(map(ref, other))
+
+    def symmetric_difference(self, other):
+        newset = self.copy()
+        newset.symmetric_difference_update(other)
+        return newset
+    __xor__ = symmetric_difference
+
+    def symmetric_difference_update(self, other):
+        self.__ixor__(other)
+    def __ixor__(self, other):
+        if self is other:
+            self.data.clear()
+        else:
+            self.data.symmetric_difference_update(ref(item, self._remove) for item in other)
+        return self
+
+    def union(self, other):
+        return self.__class__(e for s in (self, other) for e in s)
+    __or__ = union
+
+    def isdisjoint(self, other):
+        return len(self.intersection(other)) == 0
+
+    def __repr__(self):
+        return repr(self.data)
+
+    __class_getitem__ = classmethod(GenericAlias)