Specify the on-screen feedback for the Shift copy-settings gesture: a same-type eligible-target tint shown while a configuration is cached, plus a brief selection-style outline flash on both copy (source) and paste (target). All three cues share one configurable color (visuals.toml [overlays].copy_config); flashes are 0.3 s wall-clock so they play while paused and independently per building. Pure rendering, no sim state. Cross-referenced from REQ-BLD-COPY-CONFIG. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01VGNNLeFWhVzvxkK9qVXP2K