perf: find expose()'s caller from its frame instead of inspect.stack()

docs/adr/0001-expose-installs-into-modules-only.md

@@ -5,7 +5,7 @@ rejecting an empty call and raising on a name two groups both claim, and install
 module. The decision half already lives in the private, pure `_collect_fixtures`; the recurring
 proposal is to extract the install half too, wrapping the `name -> provider` mapping in a
 `FixtureSet` exposing `.install(into=...)`. We will not, because a seam needs two adapters and the
-only install targets are the caller's module, located via `inspect.stack()`, and an explicit
+only install targets are the caller's module, located through the calling frame, and an explicit
 `module=`, both `types.ModuleType`, which is one adapter exercised with two instances. Deleting a
 `FixtureSet` would bring back no complexity, since its `setattr` loop simply inlines, so the install
 step stays that loop and the public surface stays at `expose` and `modern_di_fixture`. A genuinely

modern_di_pytest/factory.py

@@ -1,4 +1,5 @@
 import inspect
+import sys
 import types
 import typing
 
@@ -129,7 +130,7 @@ def expose(
             A provider with this name raises ``ValueError``.
         pytest_scope: pytest fixture scope applied to every generated fixture.
         module: Module to install fixtures onto. Defaults to the caller's module
-            (located via ``inspect.stack()``).
+            (located via the calling frame).
 
     Example (in ``conftest.py``)::
 
@@ -144,8 +145,7 @@ def expose(
     """
     _require_groups(groups)
     if module is None:
-        frame = inspect.stack()[1].frame
-        module = inspect.getmodule(frame)
+        module = inspect.getmodule(sys._getframe(1))  # noqa: SLF001
     if module is None:
         msg = "expose() could not determine the caller module; pass module=... explicitly."
         raise RuntimeError(msg)