feat: add sandbox and local impl

backend/src/sandbox/local/local_sandbox.py

@@ -0,0 +1,46 @@
+import os
+import subprocess
+
+from src.sandbox.local.list_dir import list_dir
+from src.sandbox.sandbox import Sandbox
+
+
+class LocalSandbox(Sandbox):
+    def __init__(self, id: str):
+        super().__init__(id)
+
+    def execute_command(self, command: str) -> str:
+        result = subprocess.run(
+            command,
+            executable="/bin/zsh",
+            shell=True,
+            capture_output=True,
+            text=True,
+            timeout=30,
+        )
+        output = result.stdout
+        if result.stderr:
+            output += f"\nStd Error:\n{result.stderr}" if output else result.stderr
+        if result.returncode != 0:
+            output += f"\nExit Code: {result.returncode}"
+        return output if output else "(no output)"
+
+    def list_dir(self, path: str, max_depth=2) -> list[str]:
+        return list_dir(path, max_depth)
+
+    def read_file(self, path: str) -> str:
+        with open(path, "r") as f:
+            return f.read()
+
+    def write_file(self, path: str, content: str, append: bool = False) -> None:
+        dir_path = os.path.dirname(path)
+        if dir_path:
+            os.makedirs(dir_path, exist_ok=True)
+        mode = "a" if append else "w"
+        with open(path, mode) as f:
+            f.write(content)
+
+
+if __name__ == "__main__":
+    sandbox = LocalSandbox("test")
+    print(sandbox.list_dir("/Users/Henry/mnt"))