Handle brackets inside string arguments in split_args

[winklemad]

Description

split_args (the Colang 1.0 argument parser in nemoguardrails/colang/v1_0/lang/utils.py) treats every bracket and quote as structural. While inside a quoted string argument, a closing bracket ), ], } — or the other quote character — is still handled as syntax, so it raises ValueError and crashes flow parsing.

This hits ordinary string values: an emoticon, a citation marker, or any clause that ends with a bracket.

>>> from nemoguardrails.colang.v1_0.lang.utils import split_args
>>> split_args('msg="Hello :)"')
ValueError: Invalid syntax for string: msg="Hello :)"; expecting " and got )

It also crashes through the public parse path — any Colang 1.0 flow with such an inline string parameter fails to parse:

>>> from nemoguardrails.colang.v1_0.lang.coyml_parser import parse_flow_elements
>>> parse_flow_elements([{"user": 'ask(reason="closed ]")'}])
ValueError: Invalid syntax for string: reason="closed ]"; expecting " and got ]

The function's own docstring says it "correctly handles strings and lists/dicts", and the sibling splitters in the same module (word_split, char_split, params_tokenize) already track string state — only split_args doesn't.

Fix

Add a real in-string short-circuit: while the top of the stack is a quote, only the matching closing quote is special; brackets, commas, and the other quote type are literal text. This preserves list/dict argument parsing and still raises ValueError for genuinely unbalanced unquoted brackets (the behavior added in #2145).

Test Plan

Added test_split_args_bracket_inside_string to tests/test_parser_utils.py, covering closing brackets )]}, an emoticon, a citation marker, a comma, and the other quote character inside a quoted string, plus a bracket-in-string argument alongside a normal one. The new cases fail on develop (ValueError) and pass with the fix; the existing test_1 and the unbalanced-unquoted-bracket cases still pass.

$ pytest tests/test_parser_utils.py tests/colang
70 passed

$ ruff check nemoguardrails/colang/v1_0/lang/utils.py tests/test_parser_utils.py
All checks passed!
$ ruff format --check nemoguardrails/colang/v1_0/lang/utils.py tests/test_parser_utils.py
2 files already formatted

No linked issue — found by reading the code.

[Pouyanpi]

duplicate of #2145 note that #2144 is already closed