BSP: add Binary Space Partitioning for procedural dungeon generation

Implements #202, #203, #204, #205; partially implements #206:
- BSP class: core tree structure with bounds, split_once, split_recursive, clear
- BSPNode class: lightweight node reference with bounds, level, is_leaf,
  split_horizontal, split_position; navigation via left/right/parent/sibling;
  contains() and center() methods
- Traversal enum: PRE_ORDER, IN_ORDER, POST_ORDER, LEVEL_ORDER, INVERTED_LEVEL_ORDER
- BSP iteration: leaves() for leaf nodes only, traverse(order) for all nodes
- BSP query: find(pos) returns deepest node containing position
- BSP.to_heightmap(): converts BSP to HeightMap with select, shrink, value options

Note: #206's BSPMap subclass deferred - to_heightmap returns plain HeightMap.
The HeightMap already has all necessary operations (inverse, threshold, etc.)
for procedural generation workflows.

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

src/McRFPy_API.cpp

@@ -22,6 +22,7 @@
 #include "PyMouse.h"
 #include "UIGridPathfinding.h"  // AStarPath and DijkstraMap types
 #include "PyHeightMap.h"  // Procedural generation heightmap (#193)
+#include "PyBSP.h"  // Procedural generation BSP (#202-206)
 #include "McRogueFaceVersion.h"
 #include "GameEngine.h"
 #include "ImGuiConsole.h"
@@ -418,6 +419,7 @@ PyObject* PyInit_mcrfpy()
 
         /*procedural generation (#192)*/
         &mcrfpydef::PyHeightMapType,
+        &mcrfpydef::PyBSPType,
 
         nullptr};
 
@@ -434,6 +436,10 @@ PyObject* PyInit_mcrfpy()
         /*pathfinding iterator - returned by AStarPath.__iter__() but not directly instantiable*/
         &mcrfpydef::PyAStarPathIterType,
 
+        /*BSP internal types - returned by BSP methods but not directly instantiable*/
+        &mcrfpydef::PyBSPNodeType,
+        &mcrfpydef::PyBSPIterType,
+
         nullptr};
     
     // Set up PyWindowType methods and getsetters before PyType_Ready
@@ -448,6 +454,12 @@ PyObject* PyInit_mcrfpy()
     mcrfpydef::PyHeightMapType.tp_methods = PyHeightMap::methods;
     mcrfpydef::PyHeightMapType.tp_getset = PyHeightMap::getsetters;
 
+    // Set up PyBSPType and BSPNode methods and getsetters (#202-206)
+    mcrfpydef::PyBSPType.tp_methods = PyBSP::methods;
+    mcrfpydef::PyBSPType.tp_getset = PyBSP::getsetters;
+    mcrfpydef::PyBSPNodeType.tp_methods = PyBSPNode::methods;
+    mcrfpydef::PyBSPNodeType.tp_getset = PyBSPNode::getsetters;
+
     // Set up weakref support for all types that need it
     PyTimerType.tp_weaklistoffset = offsetof(PyTimerObject, weakreflist);
     PyUIFrameType.tp_weaklistoffset = offsetof(PyUIFrameObject, weakreflist);
@@ -555,6 +567,13 @@ PyObject* PyInit_mcrfpy()
         PyErr_Clear();
     }
 
+    // Add Traversal enum class for BSP traversal (uses Python's IntEnum)
+    PyObject* traversal_class = PyTraversal::create_enum_class(m);
+    if (!traversal_class) {
+        // If enum creation fails, continue without it (non-fatal)
+        PyErr_Clear();
+    }
+
     // Add Key enum class for keyboard input
     PyObject* key_class = PyKey::create_enum_class(m);
     if (!key_class) {