feat(ui): batch of UI polish tweaks

- admin dashboard "Users" count excludes robots (CountUsers, humans only)
- lobby finished-game delete reveal: background matches header/tab-bar (--bg-elev)
- mobile: swipe up on the zoom-out board (no staged tiles) shuffles the rack
- lobby: status icons -25%, game-row top/bottom padding halved
- toast: info tier drifts up ~a tab-bar height while fading over 2s and dismisses
  on tap; error tier unchanged
- game: confirm-move button stays pinned at the right edge; rack tiles shrink to
  fit so a full rack never overflows onto it
- telegram: a successful invite-link redeem shows a welcome window pointing at the bot
- settings: remove the grid-lines toggle; the board is always a gapless checkerboard
- settings/comms hubs: the selected tab highlight wraps icon + label as a pill

Docs: UI_DESIGN (toast, board surface, selected tab), PLAN; e2e updated for the
removed grid-lines toggle.

ui/src/lib/app.svelte.ts

@@ -56,8 +56,6 @@ export const app = $state<{
   locale: Locale;
   reduceMotion: boolean;
   boardLabels: BoardLabelMode;
-  /** Draw grid lines between board cells; off (default) is a gapless checkerboard. */
-  boardLines: boolean;
   localeLocked: boolean;
   /** Pending incoming friend requests, for the lobby ⚙️ badge and the Settings Friends tab. */
   notifications: number;
@@ -72,6 +70,10 @@ export const app = $state<{
    *  code is already used/expired, so the visitor lands in the lobby with a gentle pointer to
    *  the bot instead of a scary error on the Friends screen. */
   staleInvite: boolean;
+  /** Whether to show the Telegram "welcome" window: set when a deep-link friend code is
+   *  redeemed successfully inside Telegram, greeting the arriving player and pointing them at
+   *  the bot for the most convenient way to play. */
+  welcomeRedeem: boolean;
   /** Monotonic counter bumped when the app returns to the foreground without the live stream
    *  having dropped. An open game watches it to refetch once, recovering an in-game event shed
    *  from a full hub buffer while suspended (the stream-drop case is covered by streamAlive). */
@@ -88,12 +90,12 @@ export const app = $state<{
   locale: 'en',
   reduceMotion: false,
   boardLabels: 'beginner',
-  boardLines: false,
   localeLocked: false,
   notifications: 0,
   chatUnread: {},
   feedbackReplyUnread: false,
   staleInvite: false,
+  welcomeRedeem: false,
   resync: 0,
 });
 
@@ -143,7 +145,18 @@ function goForeground(): void {
 export function showToast(text: string, kind: Toast['kind'] = 'info'): void {
   app.toast = { kind, text, seq: ++toastSeq };
   if (toastTimer) clearTimeout(toastTimer);
-  toastTimer = setTimeout(() => (app.toast = null), 4000);
+  // An info bubble lives exactly as long as its rise-and-fade animation (2s); an error
+  // dwells longer (4s) so it is not missed.
+  toastTimer = setTimeout(() => (app.toast = null), kind === 'error' ? 4000 : 2000);
+}
+
+/** dismissToast hides the current toast at once — a tap on the bubble dismisses it. */
+export function dismissToast(): void {
+  if (toastTimer) {
+    clearTimeout(toastTimer);
+    toastTimer = null;
+  }
+  app.toast = null;
 }
 
 /** dismissStaleInvite hides the outdated-invite-link notice (the user acknowledged it). */
@@ -151,6 +164,11 @@ export function dismissStaleInvite(): void {
   app.staleInvite = false;
 }
 
+/** dismissWelcomeRedeem hides the Telegram welcome window (the user acknowledged it). */
+export function dismissWelcomeRedeem(): void {
+  app.welcomeRedeem = false;
+}
+
 /**
  * seedChatUnread sets a game's unread flag from an authoritative per-viewer REST view (the lobby
  * list, a game's state, or a move result). The live-event GameView omits the flag, so the live
@@ -476,7 +494,6 @@ export async function bootstrap(): Promise<void> {
   app.theme = prefs.theme ?? 'auto';
   app.reduceMotion = prefs.reduceMotion ?? false;
   app.boardLabels = prefs.boardLabels ?? 'beginner';
-  app.boardLines = prefs.boardLines ?? false;
   applyTheme(app.theme);
   applyReduceMotion(app.reduceMotion);
   if (prefs.locale) {
@@ -560,7 +577,13 @@ async function routeStartParam(param: string): Promise<void> {
       try {
         const friend = await gateway.friendCodeRedeem(link.code);
         navigate('/friends');
-        showToast(t('friends.added', { name: friend.displayName }));
+        // Inside Telegram a successful invite-link redeem welcomes the arriving player and
+        // points them at the bot (its native convenience); elsewhere a quiet toast suffices.
+        if (insideTelegram()) {
+          app.welcomeRedeem = true;
+        } else {
+          showToast(t('friends.added', { name: friend.displayName }));
+        }
         void refreshNotifications();
       } catch (err) {
         const code = err instanceof GatewayError ? err.code : '';
@@ -633,7 +656,6 @@ function persistPrefs(): void {
     locale: app.locale,
     reduceMotion: app.reduceMotion,
     boardLabels: app.boardLabels,
-    boardLines: app.boardLines,
   });
 }
 
@@ -686,11 +708,6 @@ export function setBoardLabels(mode: BoardLabelMode): void {
   persistPrefs();
 }
 
-export function setBoardLines(on: boolean): void {
-  app.boardLines = on;
-  persistPrefs();
-}
-
 // Background/foreground lifecycle: silence the reconnect banner during a suspend and
 // reconnect quietly on return (and refresh the lobby badge for any push missed while
 // hidden, §10). Several signals cover the platforms: the page Visibility API, the

ui/src/lib/i18n/en.ts

@@ -163,7 +163,6 @@ export const en = {
   'settings.labelsBeginner': 'Beginner',
   'settings.labelsClassic': 'Classic',
   'settings.labelsNone': 'None',
-  'settings.boardLines': 'Grid lines',
   'settings.reduceMotion': 'Reduce motion',
 
   'about.title': 'About',
@@ -241,6 +240,8 @@ export const en = {
   'friends.selfInvite': "Hopefully you've been friends with yourself for a while ☺️",
   'friends.staleInviteTitle': 'Link expired',
   'friends.staleInvite': 'You opened the game from an outdated link. Open the bot {bot} to play and get notifications.',
+  'friends.welcomeRedeemTitle': 'Welcome!',
+  'friends.welcomeRedeem': 'Welcome, {name}!\n\nUse {bot} to join games the most convenient way.',
   'friends.added': 'Added {name}.',
   'friends.blockedList': 'Blocked players',
   'friends.unblock': 'Unblock',

ui/src/lib/i18n/ru.ts

@@ -164,7 +164,6 @@ export const ru: Record<MessageKey, string> = {
   'settings.labelsBeginner': 'Новичок',
   'settings.labelsClassic': 'Классика',
   'settings.labelsNone': 'Без текста',
-  'settings.boardLines': 'Линии сетки',
   'settings.reduceMotion': 'Меньше анимаций',
 
   'about.title': 'О программе',
@@ -242,6 +241,8 @@ export const ru: Record<MessageKey, string> = {
   'friends.selfInvite': 'Надеюсь, что с собой Вы уже давно дружите ☺️',
   'friends.staleInviteTitle': 'Ссылка устарела',
   'friends.staleInvite': 'Вы открыли игру по устаревшей ссылке. Откройте бота {bot}, чтобы играть и получать уведомления.',
+  'friends.welcomeRedeemTitle': 'Добро пожаловать!',
+  'friends.welcomeRedeem': 'Добро пожаловать, {name}!\n\nВоспользуйтесь {bot}, чтобы заходить в игру наиболее удобным способом.',
   'friends.added': 'Добавлен(а) {name}.',
   'friends.blockedList': 'Заблокированные',
   'friends.unblock': 'Разблокировать',

ui/src/lib/session.ts

@@ -124,8 +124,6 @@ export interface Prefs {
   locale: Locale;
   reduceMotion: boolean;
   boardLabels: BoardLabelMode;
-  /** Draw the 1px grid lines between cells; off (default) shows a gapless checkerboard. */
-  boardLines: boolean;
 }
 
 export async function loadPrefs(): Promise<Partial<Prefs>> {