`swift-demangle` parsed a symbol beginning with `-` as an option, so
`-help` replaced the results with usage text and the call failed as
unreadable output. A symbol containing a line feed split into extra
output records, and the CRLF-tolerant parser stripped a carriage return
that belonged to the final symbol.
Pass the symbols after `--`, split records on the LF the demangler
emits, and reject multi-line symbols in the shared CLI/MCP input schema.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
