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.

docs/FUNCTIONAL.md

@@ -75,7 +75,9 @@ The lobby lists **my games** and offers a bottom tab bar — new game, statistic
 sections — *your turn*, *opponent's turn* and *finished* (empty sections are hidden) — and
 orders them so the games awaiting your move come first, the longest-waiting on top, while
 opponent-turn and finished games are most-recent first; it renders as a compact,
-line-separated list. You can **remove a finished game from your own list**:
+line-separated list. While the lobby is open and a listed game **becomes your turn or
+finishes**, its status icon **blinks twice** to draw the eye (an opponent's-turn change is
+silent, applied in place). You can **remove a finished game from your own list**:
 swipe a finished row left (or, on desktop, tap its **⋮**) to reveal a **❌**, then tap it.
 The removal is per-account and permanent — the game disappears only from your list and stays
 in the other players' lists, and there is no undo. The game types offered on **New Game** are
@@ -177,7 +179,8 @@ existing friendship). Per-game chat is for quick reactions: messages are short
 even disguised. You may send **one message per turn, on your own turn**; once it is sent
 the field gives way to a short caption until your next turn. Nudge the player whose turn
 is awaited at most once per hour (the
-nudge is part of the game chat); the out-of-app push is delivered via the platform.
+nudge is part of the game chat); both the in-app toast and the out-of-app push (delivered
+via the platform) **name the nudger** ("<opponent>: waiting for your move").
 Chat and the word-check tool share one **comms screen** with **💬 chat** / **🔎 dictionary**
 tabs, reached from the 💬 in the move-history header (with a back to the game); a new chat
 message raises an **unread badge** on the game's score bar and the 💬 until the chat is opened.