fix(tool_hints): pass max_length to abbreviate_path for is_path tools

The is_path branch in _fmt_known was not passing max_length to
abbreviate_path, so read_file, write_file, edit, list_dir, and
web_fetch always truncated paths at 40 chars regardless of config.

Now all three branches (is_path, is_command, fallback) honor the
configured toolHintMaxLength.

nanobot/utils/tool_hints.py

@@ -86,7 +86,7 @@ def _fmt_known(tc, fmt: tuple, max_length: int = 40) -> str:
     if val is None:
         return tc.name
     if fmt[2]:  # is_path
-        val = abbreviate_path(val)
+        val = abbreviate_path(val, max_len=max_length)
     elif fmt[3]:  # is_command
         val = _abbreviate_command(val, max_len=max_length)
     return fmt[1].format(val)