fix(dashboard): show full name on welcome, fix gender mismatch on trial-expired card

User reported single-letter welcome "Добро пожаловать, О!" (short first_name
"Олег"-style users) and a confused "Истекла" feminine label on the masculine
"Пробный период истёк" trial-expired card.

* Add `src/utils/displayName.ts` helper that composes `first_name + last_name`
  with `username` and `#telegram_id` fallbacks. Single source of truth for
  user-facing name rendering across the app.
* Apply `displayName(user)` in Dashboard welcome, AppHeader mobile drawer,
  and DesktopSidebar profile chip. Now a user with `first_name="О"` and
  `last_name="Иванов"` sees "О Иванов" instead of just "О".
* `SubscriptionCardExpired` — context-aware Russian label: for trial
  subscriptions render masculine "Истёк" (agrees with "пробный период"),
  for paid subscriptions keep feminine "Истекла" (agrees with "подписка").
  Uses i18next `context: subscription.is_trial ? 'trial' : ''` — falls back
  to base key for EN/ZH/FA which are grammatically neutral.
* Add `expiredDate_trial: "Истёк"` only to `ru.json` (no changes needed for
  other locales — i18next context falls back to `expiredDate`).

src/components/dashboard/SubscriptionCardExpired.tsx

@@ -228,7 +228,11 @@ export default function SubscriptionCardExpired({
       >
         <div className="flex items-center">
           <div className="mb-0.5 font-mono text-[10px] font-medium uppercase tracking-wider text-dark-50/30">
-            {isLimited ? t('dashboard.expired.activeUntil') : t('dashboard.expired.expiredDate')}
+            {isLimited
+              ? t('dashboard.expired.activeUntil')
+              : t('dashboard.expired.expiredDate', {
+                  context: subscription.is_trial ? 'trial' : '',
+                })}
           </div>
           <div className="ml-3 text-base font-bold tracking-tight text-dark-50/50">
             {formattedDate}

src/components/layout/AppShell/AppHeader.tsx

@@ -5,6 +5,7 @@ import { useState, useEffect } from 'react';
 import { initDataUser } from '@telegram-apps/sdk-react';
 
 import { useAuthStore } from '@/store/auth';
+import { displayName } from '@/utils/displayName';
 import { useShallow } from 'zustand/shallow';
 import { useTheme } from '@/hooks/useTheme';
 import { usePlatform } from '@/platform';
@@ -340,9 +341,7 @@ export function AppHeader({
                     <UserIcon className="h-5 w-5" />
                   </div>
                   <div>
-                    <div className="text-sm font-medium text-dark-100">
-                      {user?.first_name || user?.username}
-                    </div>
+                    <div className="text-sm font-medium text-dark-100">{displayName(user)}</div>
                     <div className="text-xs text-dark-500">
                       @{user?.username || `ID: ${user?.telegram_id}`}
                     </div>

src/components/layout/AppShell/DesktopSidebar.tsx

@@ -4,6 +4,7 @@ import { motion } from 'framer-motion';
 import { useQuery } from '@tanstack/react-query';
 
 import { useAuthStore } from '@/store/auth';
+import { displayName } from '@/utils/displayName';
 import {
   brandingApi,
   getCachedBranding,
@@ -188,9 +189,7 @@ export function DesktopSidebar({
             <UserIcon className="h-4 w-4 text-dark-400" />
           </div>
           <div className="min-w-0 flex-1">
-            <p className="truncate text-sm font-medium text-dark-100">
-              {user?.first_name || user?.username || `#${user?.telegram_id}`}
-            </p>
+            <p className="truncate text-sm font-medium text-dark-100">{displayName(user)}</p>
             <p className="truncate text-xs text-dark-500">
               @{user?.username || `ID: ${user?.telegram_id}`}
             </p>

src/locales/ru.json

@@ -285,6 +285,7 @@
       "traffic": "Трафик",
       "devices": "Устройства",
       "expiredDate": "Истекла",
+      "expiredDate_trial": "Истёк",
       "activeUntil": "Активна до"
     },
     "suspended": {

src/pages/Dashboard.tsx

@@ -3,6 +3,7 @@ import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import { Link, useNavigate } from 'react-router';
 import { useTranslation } from 'react-i18next';
 import { useAuthStore } from '../store/auth';
+import { displayName } from '../utils/displayName';
 import { useBlockingStore } from '../store/blocking';
 import { subscriptionApi } from '../api/subscription';
 import { referralApi } from '../api/referral';
@@ -254,7 +255,7 @@ export default function Dashboard() {
       {/* Header */}
       <div data-onboarding="welcome">
         <h1 className="text-2xl font-bold text-dark-50 sm:text-3xl">
-          {t('dashboard.welcome', { name: user?.first_name || user?.username || '' })}
+          {t('dashboard.welcome', { name: displayName(user) })}
         </h1>
         <div className="mt-1 flex flex-wrap items-center gap-2">
           <p className="text-dark-400">{t('dashboard.yourSubscription')}</p>

src/utils/displayName.ts

@@ -0,0 +1,23 @@
+/**
+ * Composes a user-facing display name from first_name + last_name with sensible fallbacks.
+ *
+ * Why: single-letter first_name (e.g., "О") looked confusing alone ("Добро пожаловать, О!").
+ * Combining with last_name makes truncated/short first names readable.
+ */
+export interface NameSource {
+  first_name?: string | null;
+  last_name?: string | null;
+  username?: string | null;
+  telegram_id?: number | null;
+}
+
+export function displayName(user?: NameSource | null): string {
+  if (!user) return '';
+  const fullName = [user.first_name, user.last_name]
+    .filter((part): part is string => Boolean(part && part.trim()))
+    .join(' ');
+  if (fullName) return fullName;
+  if (user.username) return user.username;
+  if (user.telegram_id) return `#${user.telegram_id}`;
+  return '';
+}