ui: unified rounded navbar everywhere, vertical home actions, no bot disconnect spam

- NavRail: one rounded "pill" tab bar on every screen (matches home). ScreenShell
  lays out as a portrait column and floats the nav with margins + safe-area;
  dropped the landscape side-rail variant.
- Home: the three mode cards now stack vertically as full-width rows (portrait
  friendly) instead of a 3-up landscape row.
- Disconnect: removed the simulated random opponent "disconnect" in local games
  (DISCONNECT_CHANCE) and the in-game DisconnectBanner — bots/filled seats just
  auto-play their turn; no message, no pause. (Live reconnect grace still tracked
  internally but no longer shows a banner.)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/components/GameTable.tsx

@@ -1,7 +1,7 @@
 "use client";
 
 import { AnimatePresence, motion } from "framer-motion";
-import { Crown, Flag, LogOut, SmilePlus, Volume2, VolumeX, WifiOff, Zap } from "lucide-react";
+import { Crown, Flag, LogOut, SmilePlus, Volume2, VolumeX, Zap } from "lucide-react";
 import { useEffect, useMemo, useState } from "react";
 import { useGameStore } from "@/lib/game-store";
 import { useSoundStore } from "@/lib/sound-store";
@@ -210,7 +210,6 @@ export function GameTable({
         <TurnTimer />
         <TurnIndicator />
       </div>
-      <DisconnectBanner />
       <Reactions />
       <ShortcutsHint />
 
@@ -734,33 +733,6 @@ function TurnTimer() {
   );
 }
 
-function DisconnectBanner() {
-  const seat = useGameStore((s) => s.disconnectedSeat);
-  const deadline = useGameStore((s) => s.reconnectDeadline);
-  const name = useGameStore((s) => (seat != null ? s.seatPlayers[seat]?.name : null));
-  const secs = useCountdown(deadline);
-  const { t } = useI18n();
-  return (
-    <AnimatePresence>
-      {seat != null && (
-        <motion.div
-          initial={{ opacity: 0, y: -10 }}
-          animate={{ opacity: 1, y: 0 }}
-          exit={{ opacity: 0 }}
-          className="absolute top-1/2 left-1/2 -translate-x-1/2 -translate-y-1/2 z-40"
-        >
-          <div className="glass rounded-2xl px-4 py-3 flex items-center gap-2.5 text-sm">
-            <WifiOff className="size-5 text-rose-300 animate-pulse" />
-            <span className="text-cream/90">
-              {t("dc.waiting", { name: name ?? "", s: secs ?? 0 })}
-            </span>
-          </div>
-        </motion.div>
-      )}
-    </AnimatePresence>
-  );
-}
-
 /* ----------------------------- Reactions ------------------------------ */
 
 const REACTION_POS: Record<number, string> = {