feat(files-mcp): business wrappers and Pydantic request models

Adds files_mcp/tools/requests.py with 9 Pydantic body models (one per
tool, since fastapi-mcp passes args as JSON body) and
files_mcp/tools/files.py with 9 thin wrappers that call path_guard
then fs_ops and return model_dump() form. Adds tests/unit/test_files_tool.py
covering happy path, sandbox escape, and KeyError/FileExistsError
propagation for each wrapper.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

files_mcp/tools/files.py

@@ -0,0 +1,76 @@
+# coding=utf-8
+"""
+@Time   :2026/6/30
+@Author :tao.chen
+
+Business wrappers: each tool function logs on entry, calls path_guard
+on every user-supplied path, delegates to fs_ops, and returns the
+Pydantic-serialized result. No business logic of its own — same shape
+as spark_executor/tools/connections.py.
+"""
+from common.logging import logger
+from files_mcp.core import fs_ops, path_guard
+
+
+def create_file(*, path: str, content: str, overwrite: bool = False) -> dict:
+    logger.debug(
+        f"create_file enter path={path} content_len={len(content)} overwrite={overwrite}"
+    )
+    p = path_guard.resolve_and_check(path)
+    return fs_ops.create(p, content, overwrite).model_dump()
+
+
+def read_file(*, path: str) -> dict:
+    logger.debug(f"read_file enter path={path}")
+    p = path_guard.resolve_and_check(path)
+    return fs_ops.read(p)
+
+
+def update_file(*, path: str, content: str) -> dict:
+    logger.debug(f"update_file enter path={path} content_len={len(content)}")
+    p = path_guard.resolve_and_check(path)
+    return fs_ops.update(p, content).model_dump()
+
+
+def delete_file(*, path: str, recursive: bool = False) -> dict:
+    logger.debug(f"delete_file enter path={path} recursive={recursive}")
+    p = path_guard.resolve_and_check(path)
+    return fs_ops.delete(p, recursive).model_dump()
+
+
+def list_dir(
+    *, path: str, recursive: bool = False, max_depth: int = 1
+) -> dict:
+    logger.debug(
+        f"list_dir enter path={path} recursive={recursive} max_depth={max_depth}"
+    )
+    p = path_guard.resolve_and_check(path)
+    return {"path": str(p), "entries": [e.model_dump() for e in fs_ops.list_dir(p, recursive, max_depth)]}
+
+
+def stat(*, path: str) -> dict:
+    logger.debug(f"stat enter path={path}")
+    p = path_guard.resolve_and_check(path)
+    return fs_ops.stat(p).model_dump()
+
+
+def search(*, path: str, pattern: str, recursive: bool = True) -> dict:
+    logger.debug(
+        f"search enter path={path} pattern={pattern!r} recursive={recursive}"
+    )
+    p = path_guard.resolve_and_check(path)
+    return {"pattern": pattern, "matches": fs_ops.search(p, pattern, recursive)}
+
+
+def move(*, src: str, dst: str, overwrite: bool = False) -> dict:
+    logger.debug(f"move enter src={src} dst={dst} overwrite={overwrite}")
+    s = path_guard.resolve_and_check(src)
+    d = path_guard.resolve_and_check(dst)
+    return fs_ops.move(s, d, overwrite).model_dump()
+
+
+def copy(*, src: str, dst: str, overwrite: bool = False) -> dict:
+    logger.debug(f"copy enter src={src} dst={dst} overwrite={overwrite}")
+    s = path_guard.resolve_and_check(src)
+    d = path_guard.resolve_and_check(dst)
+    return fs_ops.copy(s, d, overwrite).model_dump()