Splash now renders a bordered narrow-tier panel with the full braille
sloth banner and wraps verb lists instead of truncating with ellipsis.
REPL pins editor to the bottom and exposes runTurnFactory while keeping
the pre-v5.3 runTurn prop working. Slash commands move into a
single-source catalog (tui/slash_commands.mjs) and a dedicated popup
component (tui/slash_popup.mjs).

Verified: 368/368 tests pass, three verifier reports pass, non-TTY
fallback still streams planner output to stdout.