When a tool sets ResponseHandled=true (e.g., send_file), the turn ends
without producing a final assistant response. This meant no outbound
message triggered FinalizeToolFeedbackMessage, leaving the animation
goroutine running indefinitely — editing the Feishu card every 3 seconds
with "." / ".." suffixes long after the tool had finished.
Fix: call DismissToolFeedback at "Tool output satisfied delivery" so the
tracker is cleared and the animation goroutine is stopped immediately.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>