Models frequently hallucinate a 'directory' parameter alongside filePath,
causing hard failures. Instead of rejecting, accept directory as an alias
for filePath and gracefully handle when both are provided (prefer filePath).
This prevents the 'filePath and directory are mutually exclusive' error
that users hit when models pass both parameters.
Fixes model confusion with lsp_diagnostics tool parameters.
YeonGyu-Kim
8f4554e115