UI: даты игр в едином формате ДД.ММ.ГГГГ вместо сырых ISO-строк

Новый formatDate в domain/format.ts для date-only строк (played_at,
last_match_at). Применён: список партий, заголовок страницы партии
(раньше там было «2026-07-13»), записи в админке, «последняя партия»
на странице группы.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

frontend/src/pages/GroupPage.tsx

@@ -6,6 +6,7 @@ import { GroupSwitcher } from "../components/GroupSwitcher";
 import { Leaderboard } from "../components/Leaderboard";
 import { MatchListView } from "../components/MatchList";
 import { Spinner } from "../components/Spinner";
+import { formatDate } from "../domain/format";
 import { useMe } from "../hooks/auth";
 import { useGroup, useGroupMatches, useGroupStats } from "../hooks/groups";
 
@@ -49,7 +50,7 @@ export function GroupPage() {
         </div>
         <p className="muted small">
           Партий: {stats?.total_matches ?? 0}
-          {stats?.last_match_at ? ` · последняя: ${stats.last_match_at}` : ""}
+          {stats?.last_match_at ? ` · последняя: ${formatDate(stats.last_match_at)}` : ""}
         </p>
       </div>
 

frontend/src/pages/MatchDetailPage.tsx

@@ -6,7 +6,7 @@ import { ConfirmDialog } from "../components/ConfirmDialog";
 import { MatchMedia } from "../components/MatchMedia";
 import { PlayerLink } from "../components/PlayerLink";
 import { Spinner } from "../components/Spinner";
-import { formatDuration, formatTime } from "../domain/format";
+import { formatDate, formatDuration, formatTime } from "../domain/format";
 import { WIN_REASONS, type WinReason, winReasonLabel } from "../domain/winReasons";
 import { useToast } from "../context/ToastContext";
 import {
@@ -120,7 +120,7 @@ export function MatchDetailPage() {
     <div>
       <div className="card">
         <div className="row-between">
-          <h2 style={{ margin: 0 }}>{match.played_at}</h2>
+          <h2 style={{ margin: 0 }}>{formatDate(match.played_at)}</h2>
           {inProgress ? (
             <span className="badge" style={{ color: "var(--accent-2)" }}>идёт</span>
           ) : (

frontend/src/pages/admin/AdminRecordsPage.tsx

@@ -3,6 +3,7 @@ import { useMemo, useState } from "react";
 
 import { ApiError } from "../../api/client";
 import { ConfirmDialog } from "../../components/ConfirmDialog";
+import { formatDate } from "../../domain/format";
 import { Spinner } from "../../components/Spinner";
 import { Switch } from "../../components/Switch";
 import { useToast } from "../../context/ToastContext";
@@ -54,7 +55,7 @@ export function AdminRecordsPage() {
     <div key={m.id} className="card" style={{ margin: 0 }}>
       <div className="row-between">
         <div>
-          <b>#{m.id}</b> · {m.played_at}
+          <b>#{m.id}</b> · {formatDate(m.played_at)}
           {!grouped && <span className="muted small"> · {m.group_name}</span>}
           <div className="muted small">
             {m.player_count} игр. · автор {m.created_by}