normalizeTomlText replaced every curly/fullwidth quote in the text before
TOML parsing, including quotes inside already-valid strings. MCP import and
validation (tomlUtils, mcpDraft) and the Codex config editor therefore
silently rewrote values such as args = ["don’t"] to "don't", and rejected
valid configs like args = ["say“hello”"] or args = ['don’t'] because the
inner quotes became delimiters.
Scan the text instead: smart quotes outside strings are delimiters and
become ASCII; strings opened by an ASCII quote keep smart quotes as
content; strings opened by a smart quote may close with either form;
multi-line strings and comments are handled. To keep the Chinese IME case
working (the editor normalizes each keystroke, so the left quote is already
ASCII when the right smart quote is typed), an ASCII-opened string left
unterminated at end of line is re-scanned with smart closers, and if the
strict result still fails to parse, a lenient scan is used only when it
parses. Escaped smart double quotes in basic strings become \". Text
without smart quotes is returned unchanged.
Refs #8559
