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>

main.py

@@ -396,6 +396,68 @@ def typecheck_stubs(versions: list[str] | None = None) -> None:
         sys.exit(1)
 
 
+def conformance_check(versions: list[str] | None = None) -> None:
+    """Type-check conformance test files against generated stubs."""
+    dist_dir = SCRIPT_DIR / "dist"
+    conformance_dir = SCRIPT_DIR / "conformance"
+
+    if not conformance_dir.exists():
+        print("No conformance/ directory found.")
+        sys.exit(1)
+
+    if versions:
+        missing = [v for v in versions if not (dist_dir / v).is_dir()]
+        if missing:
+            print(f"Missing stubs for: {', '.join(missing)}")
+            sys.exit(1)
+    else:
+        versions = sorted(
+            d.name
+            for d in dist_dir.iterdir()
+            if d.is_dir() and not d.name.startswith(".")
+        )
+
+    if not versions:
+        print("No generated stubs found in dist/.")
+        sys.exit(1)
+
+    failed = False
+    for version in versions:
+        version_dir = dist_dir / version
+        print(f"=== Conformance check against Blender {version} stubs ===")
+
+        python_version_file = version_dir / ".python-version"
+        python_version = (
+            python_version_file.read_text().strip()
+            if python_version_file.exists()
+            else "3.11"
+        )
+
+        config = version_dir / "pyrightconfig.conformance.json"
+        config.write_text(
+            json.dumps(
+                {
+                    "include": [str(conformance_dir)],
+                    "extraPaths": [str(version_dir)],
+                    "typeCheckingMode": "strict",
+                    "pythonVersion": python_version,
+                }
+            )
+        )
+
+        result = subprocess.run(
+            ["basedpyright", "--project", str(config)],
+        )
+
+        config.unlink()
+
+        if result.returncode != 0:
+            failed = True
+
+    if failed:
+        sys.exit(1)
+
+
 if __name__ == "__main__":
     parser = argparse.ArgumentParser(description="Blender type stubs generator")
     parser.add_argument(
@@ -403,6 +465,11 @@ if __name__ == "__main__":
         action="store_true",
         help="Type-check generated stubs instead of generating",
     )
+    parser.add_argument(
+        "--conformance",
+        action="store_true",
+        help="Run conformance tests against generated stubs",
+    )
     parser.add_argument(
         "versions",
         nargs="*",
@@ -412,6 +479,8 @@ if __name__ == "__main__":
 
     if args.typecheck_stubs:
         typecheck_stubs(args.versions or None)
+    elif args.conformance:
+        conformance_check(args.versions or None)
     else:
         if not args.versions:
             parser.error("versions are required for generation")