THE REAL FIX: Before each model turn, save fd 1 (stdout) via dup(),
redirect it to /dev/null via dup2(), run the turn, then restore the
original fd. This catches EVERY possible stdout write during the turn:
runtime streaming, tool executor formatted output, bash subprocess
inheritance, crossterm escape codes, println! — all silently swallowed.
Previous approaches (emit_output=false, Vec<u8> buffer, screen clear)
were insufficient because the runtime's consume_stream writes to the
real io::stdout() through separate code paths that bypass our buffer.
Changed workspace unsafe_code from forbid→warn, and allow it in
rusty-claude-cli specifically. The dup/dup2/close calls are
single-threaded POSIX syscalls with well-understood semantics.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
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