chore: import upstream snapshot with attribution

setup.py

@@ -0,0 +1,87 @@
+from __future__ import annotations
+
+from collections import defaultdict
+from pathlib import Path
+import tempfile
+
+from setuptools import setup
+from setuptools.command.build import build as _build
+from setuptools.command.egg_info import egg_info as _egg_info
+
+
+REPO_ROOT = Path(__file__).parent.resolve()
+
+
+def _source_tree_is_writable() -> bool:
+    probe = REPO_ROOT / ".setuptools-write-probe"
+    try:
+        with probe.open("w", encoding="utf-8") as handle:
+            handle.write("")
+        probe.unlink()
+    except OSError:
+        try:
+            probe.unlink(missing_ok=True)
+        except OSError:
+            pass
+        return False
+    return True
+
+
+def _temporary_build_dir(kind: str) -> str:
+    return tempfile.mkdtemp(prefix=f"hermes-agent-{kind}-")
+
+
+def _would_write_under_source(path_value: str | None) -> bool:
+    if path_value is None:
+        return True
+    path = Path(path_value)
+    if not path.is_absolute():
+        path = REPO_ROOT / path
+    try:
+        path.resolve().relative_to(REPO_ROOT)
+    except ValueError:
+        return False
+    return True
+
+
+class ReadOnlySourceBuild(_build):
+    def finalize_options(self) -> None:
+        if (
+            not _source_tree_is_writable()
+            and _would_write_under_source(self.build_base)
+        ):
+            self.build_base = _temporary_build_dir("build")
+        super().finalize_options()
+
+
+class ReadOnlySourceEggInfo(_egg_info):
+    def finalize_options(self) -> None:
+        if (
+            not _source_tree_is_writable()
+            and _would_write_under_source(self.egg_base)
+        ):
+            self.egg_base = _temporary_build_dir("egg-info")
+        super().finalize_options()
+
+
+def _data_file_tree(root_name: str) -> list[tuple[str, list[str]]]:
+    root = REPO_ROOT / root_name
+    grouped: defaultdict[str, list[str]] = defaultdict(list)
+    for path in sorted(root.rglob("*")):
+        if not path.is_file():
+            continue
+        rel_path = path.relative_to(REPO_ROOT)
+        grouped[str(rel_path.parent)].append(str(rel_path))
+    return sorted(grouped.items())
+
+
+setup(
+    cmdclass={
+        "build": ReadOnlySourceBuild,
+        "egg_info": ReadOnlySourceEggInfo,
+    },
+    data_files=[
+        *_data_file_tree("skills"),
+        *_data_file_tree("optional-skills"),
+    ]
+)