raise on malformed array element instead of dropping it

[netliomax25-code]

Summary

Repro: parse a = [{1] or a = [1, {2], an inline table that never reaches its =.
Cause: _parse_array caught the UnexpectedCharError from the element's _parse_value and dropped it, so the cursor was left sitting on ] and the array came back truncated ([], [1]) rather than failing on the bad element.
Fix: let the element parse error propagate. The existing self._current != "]" guard already handles the empty / trailing-comma case that except was covering, so nothing valid changes.

Adds a regression test in tests/test_parser.py; full suite including the toml-test 1.1 cases stays green.

Agent Drafting Metadata

• Agent:
• Model:
• Notes: