Add minimal reproduction for ty#2243 cycle crash

Regression test for https://github.com/astral-sh/ty/issues/2243

Reduced to 20 lines. The crash requires this specific combination:
1. A TypeVar with a forward-reference union bound
2. A Callable type alias using that TypeVar
3. A Protocol using Self returning another Protocol with that TypeVar
4. A subclass Protocol inheriting from the parent with the TypeVar
5. Another Protocol using ExprT (bounded by forward ref) in a method

crates/ty_python_semantic/resources/corpus/cyclic_callable_typevar_bound.py

@@ -0,0 +1,34 @@
+"""Minimal reproduction for ty cycle crash (20 lines).
+
+Regression test for https://github.com/astral-sh/ty/issues/2243
+
+The crash requires this specific combination:
+1. A TypeVar with a forward-reference union bound: `TypeVar("T", bound="X[Any] | int")`
+2. A Callable type alias using that TypeVar: `TypeAlias = Callable[[T], None]`
+3. A Protocol using Self in a method returning another Protocol with that TypeVar
+4. A subclass Protocol inheriting from the parent with the TypeVar
+5. Another Protocol using ExprT (bounded by forward ref) in a method
+
+Run with: ty check --python-version 3.14
+Expected: Should not crash with "too many cycle iterations"
+"""
+from collections.abc import Callable
+from typing import Protocol, Self, Any, TypeVar, TypeAlias
+
+FrameT = TypeVar("FrameT", bound="Frame[Any] | int")
+Fn: TypeAlias = Callable[[FrameT], None]
+ExprT = TypeVar("ExprT", bound="Expr[Any]")
+
+class NS(Protocol[FrameT, ExprT]):
+    def when(self) -> Then[FrameT]: ...
+
+class Expr(Protocol[FrameT]):
+    def ns(self) -> NS[FrameT, Self]: ...
+    @classmethod
+    def col(cls, f: Fn[FrameT]) -> Self: ...
+
+class Then(Expr[FrameT], Protocol[FrameT]):
+    pass
+
+class Frame(Protocol[ExprT]):
+    def with_columns(self, e: ExprT) -> None: ...