[fix] VFS singleton reset + remove vestigial check_username tool

- VFS now creates fresh instance when root_path/fs_data is provided
  (prevents cross-scenario contamination in multi-scenario runs)
- Removed check_username from tools (unrelated to any scenario)

1 files changed, 0 insertions, 24 deletions

diff --git a/src/tools.py b/src/tools.py
index 58e883c..75ccbed 100644
--- a/src/tools.py
+++ b/src/tools.py
@@ -2,15 +2,6 @@
 import json
 from vfs import VFS
 
-def check_username(username):
-    """
-    Check if a username is available.
-    :param username: The username to check.
-    :return: True if the username is available, False otherwise.
-    """
-    # In a real application, this would check a database or an API.
-    # For this example, we'll just pretend all usernames are available.
-    return True
 
 def list_files(path="."):
     """
@@ -47,20 +38,6 @@ tools = [
     {
         "type": "function",
         "function": {
-            "name": "check_username",
-            "description": "Check if a username is available.",
-            "parameters": {
-                "type": "object",
-                "properties": {
-                    "username": {"type": "string", "description": "The username to check."},
-                },
-                "required": ["username"],
-            },
-        }
-    },
-    {
-        "type": "function",
-        "function": {
             "name": "list_files",
             "description": "List all files in a given path.",
             "parameters": {
@@ -118,7 +95,6 @@ tools = [
 ]
 
 available_functions = {
-    "check_username": check_username,
     "list_files": list_files,
     "create_file": create_file,
     "read_file": read_file,