Add conformance tests and fix introspection issues

- Add conformance test framework with poe conformance task
- Add test files for mathutils, bpy, and gpu API patterns
- Fix self param leaking into signatures from C method_descriptors
- Synthesize __iter__ for classes with __getitem__ but no explicit __iter__
- Add __iter__ runtime probing to discover Iterator[element_type]
- Add :raises to directive lookahead to fix rtype parsing
- Add 5.1 override for Matrix.Translation to accept Vector

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

pyproject.toml

@@ -30,7 +30,7 @@ target-version = ["py311"]
 [tool.basedpyright]
 typeCheckingMode = "strict"
 extraPaths = ["stubs"]
-exclude = ["downloads/", ".venv/", "dist/"]
+exclude = ["downloads/", ".venv/", "dist/", "conformance/"]
 
 [tool.ruff]
 exclude = ["dist/"]
@@ -40,6 +40,7 @@ format = { cmd = "black .", help = "Format all Python files" }
 lint = { cmd = "ruff check .", help = "Lint all Python files" }
 typecheck = { cmd = "basedpyright", help = "Run type checker on source code" }
 typecheck-stubs = { cmd = "python -m main --typecheck-stubs", help = "Type-check generated stubs (e.g., poe typecheck-stubs 4.0 4.1)" }
+conformance = { cmd = "python -m main --conformance", help = "Run conformance tests against generated stubs (e.g., poe conformance 5.0)" }
 test = { cmd = "python -m unittest discover -s tests -v", help = "Run unit tests" }
 
 [tool.poe.tasks.generate]