fix(mcp): preserve stdio argv passthrough

tools/mcp_tool.py

@@ -268,6 +268,38 @@ _SAFE_ENV_KEYS = frozenset({
     "PATH", "HOME", "USER", "LANG", "LC_ALL", "TERM", "SHELL", "TMPDIR",
 })
 
+_SAFE_ENV_KEYS_CASE_INSENSITIVE = frozenset({
+    # Windows process/location vars. These are needed by launcher-style tools
+    # such as Docker Desktop's MCP plugin discovery, and do not carry secrets.
+    "ALLUSERSPROFILE",
+    "APPDATA",
+    "COMMONPROGRAMFILES",
+    "COMMONPROGRAMFILES(X86)",
+    "COMMONPROGRAMW6432",
+    "COMPUTERNAME",
+    "COMSPEC",
+    "HOMEDRIVE",
+    "HOMEPATH",
+    "LOCALAPPDATA",
+    "NUMBER_OF_PROCESSORS",
+    "OS",
+    "PATHEXT",
+    "PROCESSOR_ARCHITECTURE",
+    "PROGRAMDATA",
+    "PROGRAMFILES",
+    "PROGRAMFILES(X86)",
+    "PROGRAMW6432",
+    "PUBLIC",
+    "SYSTEMDRIVE",
+    "SYSTEMROOT",
+    "TEMP",
+    "TMP",
+    "USERDOMAIN",
+    "USERNAME",
+    "USERPROFILE",
+    "WINDIR",
+})
+
 # Regex for credential patterns to strip from error messages
 _CREDENTIAL_PATTERN = re.compile(
     r"(?:"
@@ -305,7 +337,11 @@ def _build_safe_env(user_env: Optional[dict]) -> dict:
     """
     env = {}
     for key, value in os.environ.items():
-        if key in _SAFE_ENV_KEYS or key.startswith("XDG_"):
+        if (
+            key in _SAFE_ENV_KEYS
+            or key.upper() in _SAFE_ENV_KEYS_CASE_INSENSITIVE
+            or key.startswith("XDG_")
+        ):
             env[key] = value
     if user_env:
         env.update(user_env)