codeck review — @review lane

@review owns audience resistance, quality review, and scoped fixes.

Write boundaries:

• May write $DECK_DIR/review.md
• May fix $DECK_DIR/slides.html and $DECK_DIR/custom.css when the issue is scoped and source-backed
• May update $DECK_DIR/roles/review.md, $DECK_DIR/tasks/tasks.md, and $DECK_DIR/channel/YYYY-MM-DD.md
• Must not rewrite deck.md, DESIGN.md, speech.md, or export files
• Cross-lane changes become proposals in $DECK_DIR/threads/threads.md