feat(nudge): name the sender; blink lobby cards; re-animate toasts

The "waiting for your move" popup was the nudge (chat.nudge), shown without a
sender name. Resolve the nudger's per-game seat name server-side and carry it on
a new NudgeEvent.sender_name field, so:

- the in-app toast reads "<opponent>: Waiting for your move 🤭" (chat.nudgeBy);
- the out-of-app Telegram push names the sender too (render nudgeBy);

falling back to the plain phrase when the name is absent (RU mirrored). The
your_turn toast already named the opponent and is unchanged.

Lobby: when a card transitions into "your turn" or "finished" while the lobby is
open, its status emoji blinks twice (two 1s fades); the opponent's-turn change
stays in place. Blink state is keyed by game id (SvelteSet + per-id nonce/timer)
so overlapping events animate in isolation; suppressed under reduce-motion.

Toast: a per-message seq re-keys Toast.svelte, so the freshest toast cancels the
previous one and replays its entrance, uniformly on every screen.

Tests: notify.Nudge round-trip + render named/fallback (Go), game.Service.SeatName
(integration), codec/i18n/gamePhase/shouldBlink (UI). Docs (FUNCTIONAL +_ru,
UI_DESIGN) + PLAN TODO-7 (deferred FLIP card-relocation animation) updated.

platform/telegram/internal/render/render.go

@@ -37,7 +37,7 @@ func Render(kind string, payload []byte, lang string) (Message, bool) {
 		return Message{Text: gameOverText(ev, p), ButtonText: p.openGame, StartParam: deeplink.Game(string(ev.GameId()))}, true
 	case "nudge":
 		ev := scrabblefb.GetRootAsNudgeEvent(payload, 0)
-		return Message{Text: p.nudge, ButtonText: p.openGame, StartParam: deeplink.Game(string(ev.GameId()))}, true
+		return Message{Text: nudgeText(ev, p), ButtonText: p.openGame, StartParam: deeplink.Game(string(ev.GameId()))}, true
 	case "match_found":
 		ev := scrabblefb.GetRootAsMatchFoundEvent(payload, 0)
 		return Message{Text: p.matchFound, ButtonText: p.openGame, StartParam: deeplink.Game(string(ev.GameId()))}, true
@@ -76,6 +76,16 @@ func yourTurnText(ev *scrabblefb.YourTurnEvent, p phrases) string {
 	}
 }
 
+// nudgeText renders the nudge body, voiced as the sender who is waiting ("{name}: Waiting for
+// your move 🤭"). It falls back to the plain phrase when the sender name is missing (an older
+// backend, or an unresolved name).
+func nudgeText(ev *scrabblefb.NudgeEvent, p phrases) string {
+	if name := string(ev.SenderName()); name != "" {
+		return fmt.Sprintf(p.nudgeBy, name)
+	}
+	return p.nudge
+}
+
 // gameOverText renders the "game over" body from the recipient's own perspective.
 func gameOverText(ev *scrabblefb.GameOverEvent, p phrases) string {
 	score := string(ev.ScoreLine())
@@ -89,9 +99,9 @@ func gameOverText(ev *scrabblefb.GameOverEvent, p phrases) string {
 	}
 }
 
-// phrases is one language's message catalog. The yourTurn*/gameOver* entries are fmt format
-// strings: yourTurnPlay takes (name, word, scoreLine); yourTurnExchange/Pass/Moved take (name);
-// the gameOver* entries take (scoreLine).
+// phrases is one language's message catalog. The yourTurn*/gameOver*/nudgeBy entries are fmt
+// format strings: yourTurnPlay takes (name, word, scoreLine); yourTurnExchange/Pass/Moved and
+// nudgeBy take (name); the gameOver* entries take (scoreLine).
 type phrases struct {
 	yourTurn         string
 	yourTurnPlay     string
@@ -102,6 +112,7 @@ type phrases struct {
 	gameOverLost     string
 	gameOverDraw     string
 	nudge            string
+	nudgeBy          string
 	matchFound       string
 	invitation       string
 	friendRequest    string
@@ -119,6 +130,7 @@ var english = phrases{
 	gameOverLost:     "Game over — you lost. Score %s",
 	gameOverDraw:     "Game over — a draw. Score %s",
 	nudge:            "You were nudged — it's your turn.",
+	nudgeBy:          "%s: Waiting for your move 🤭",
 	matchFound:       "Your game is ready.",
 	invitation:       "You have a new game invitation.",
 	friendRequest:    "You have a new friend request.",
@@ -136,6 +148,7 @@ var russian = phrases{
 	gameOverLost:     "Игра окончена — вы проиграли. Счёт %s",
 	gameOverDraw:     "Игра окончена — ничья. Счёт %s",
 	nudge:            "Вас поторопили — ваш ход.",
+	nudgeBy:          "%s: Жду Вашего хода 🤭",
 	matchFound:       "Игра найдена.",
 	invitation:       "Вас пригласили в игру.",
 	friendRequest:    "Вам пришла заявка в друзья.",