feat: random generators, frozenset and __hash__/__iter__/__getitem__/__contains__ in Ren'Py python

renpy.random/random get choices, sample, randrange and Random(seed); frozenset, iter and hash
are builtins. User classes may define __hash__ (dict keys), __iter__, __getitem__ and
__contains__; the converter accepts them instead of rejecting the whole class, which
removes the Perk/Skill/Status wall in SaintlyCorruption.

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

backend/app/converter/pyexpr.py

@@ -264,7 +264,8 @@ def stmt(node: ast.stmt) -> list[Stmt]:
 
 # Methods the player can run implicitly. Any other dunder method would silently
 # never be called, so the converter refuses it instead.
-SUPPORTED_DUNDERS = {"__init__", "__str__", "__repr__", "__call__", "__eq__"}
+SUPPORTED_DUNDERS = {"__init__", "__str__", "__repr__", "__call__", "__eq__", "__hash__", "__iter__", "__getitem__",
+                     "__contains__"}
 INACTIVE_VARIANTS = {"gui.variant", "renpy.variant"}
 TRANSPARENT_DECORATORS = {"renpy.pure"}  # marks a function as side-effect free; no runtime meaning
 DECORATORS = {"staticmethod", "classmethod", "property"}