feat(client): initialize procurement tool skeleton

client/src/cmbuyer_client/runtime.py

@@ -0,0 +1,42 @@
+"""采购工具的本地运行目录策略。"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+import os
+from pathlib import Path
+
+
+@dataclass(frozen=True)
+class RuntimePaths:
+    """仅包含应用生成物的本地目录。
+
+    日志和证据产物不落在源码树中，避免把含有现场信息的运行数据误提交到 Git。
+    """
+
+    root: Path
+    logs: Path
+    artifacts: Path
+
+    @classmethod
+    def from_root(cls, root: Path) -> "RuntimePaths":
+        resolved_root = root.expanduser()
+        return cls(
+            root=resolved_root,
+            logs=resolved_root / "logs",
+            artifacts=resolved_root / "artifacts",
+        )
+
+    @classmethod
+    def default(cls) -> "RuntimePaths":
+        local_app_data = os.environ.get("LOCALAPPDATA")
+        if local_app_data:
+            return cls.from_root(Path(local_app_data) / "cmbuyer")
+
+        return cls.from_root(Path.home() / ".local" / "share" / "cmbuyer")
+
+    def ensure_exists(self) -> None:
+        """创建运行目录；调用方负责向用户呈现无法创建目录的错误。"""
+
+        self.logs.mkdir(parents=True, exist_ok=True)
+        self.artifacts.mkdir(parents=True, exist_ok=True)