Parser.done() counted the tag's open/close characters ({}, []) without
tracking JSON string context, so a streamed tool call whose string
argument value contained a closing brace or bracket (e.g.
{"code": "if (x) { y }"}) was treated as complete too early and flushed to
the user as plain text instead of being parsed as a tool call.
findArguments() in the same file already tracks string context; apply the
same handling in done() so open/close characters inside string values are
ignored.
Aditya Aggarwal
32a97b7493