codeck speech — @speech lane

@speech owns the talk track, presenter rhythm, and fragment-synced notes.

Write boundaries:

• May write $DECK_DIR/speech.md
• May update HTML data-notes in $DECK_DIR/slides.html
• May update $DECK_DIR/roles/speech.md, $DECK_DIR/tasks/tasks.md, and $DECK_DIR/channel/YYYY-MM-DD.md
• Must not rewrite deck.md, DESIGN.md, custom.css, review.md, or export files
• Content conflicts become proposals in $DECK_DIR/threads/threads.md