feat(i18n): migrate all hardcoded Russian text to i18n

- Replace all hardcoded Russian strings with t() calls across 30+ files
- Add ~500 new translation keys to all 4 locales (ru, en, zh, fa)
- Convert module-level config objects to labelKey pattern
- Remove Russian fallbacks from t() calls (fallbackLng handles it)
- Replace DeepLinkRedirect custom i18n with standard t() calls
- Fix subscription.servers key collision (string vs object)

src/components/admin/SettingInput.tsx

@@ -1,4 +1,5 @@
 import { useState, useRef, useEffect } from 'react';
+import { useTranslation } from 'react-i18next';
 import { SettingDefinition } from '../../api/adminSettings';
 import { CheckIcon, CloseIcon, EditIcon } from './icons';
 
@@ -32,6 +33,7 @@ function isListOrJsonKey(key: string): boolean {
 }
 
 export function SettingInput({ setting, onUpdate, disabled }: SettingInputProps) {
+  const { t } = useTranslation();
   const [isEditing, setIsEditing] = useState(false);
   const [value, setValue] = useState('');
   const textareaRef = useRef<HTMLTextAreaElement>(null);
@@ -95,24 +97,24 @@ export function SettingInput({ setting, onUpdate, disabled }: SettingInputProps)
             if (e.key === 'Enter' && (e.ctrlKey || e.metaKey)) handleSave();
           }}
           autoFocus
-          placeholder="Введите значение..."
+          placeholder={t('admin.settings.inputPlaceholder')}
           className="min-h-[100px] w-full resize-none rounded-xl border border-accent-500 bg-dark-700 px-4 py-3 font-mono text-sm text-dark-100 focus:outline-none focus:ring-2 focus:ring-accent-500/30"
         />
         <div className="flex items-center justify-between gap-2">
-          <span className="text-xs text-dark-500">Ctrl+Enter для сохранения</span>
+          <span className="text-xs text-dark-500">{t('admin.settings.ctrlEnterHint')}</span>
           <div className="flex items-center gap-2">
             <button
               onClick={handleCancel}
               className="rounded-lg bg-dark-600 px-3 py-1.5 text-sm text-dark-300 transition-colors hover:bg-dark-500"
             >
-              Отмена
+              {t('admin.settings.cancelButton')}
             </button>
             <button
               onClick={handleSave}
               className="flex items-center gap-1.5 rounded-lg bg-accent-500 px-3 py-1.5 text-sm text-white transition-colors hover:bg-accent-600"
             >
               <CheckIcon />
-              Сохранить
+              {t('admin.settings.saveButton')}
             </button>
           </div>
         </div>
@@ -134,20 +136,20 @@ export function SettingInput({ setting, onUpdate, disabled }: SettingInputProps)
             if (e.key === 'Escape') handleCancel();
           }}
           autoFocus
-          placeholder="Введите значение..."
+          placeholder={t('admin.settings.inputPlaceholder')}
           className="w-48 rounded-lg border border-accent-500 bg-dark-700 px-3 py-2 text-sm text-dark-100 focus:outline-none focus:ring-2 focus:ring-accent-500/30 sm:w-56"
         />
         <button
           onClick={handleSave}
           className="rounded-lg bg-accent-500 p-2 text-white transition-colors hover:bg-accent-600"
-          title="Сохранить (Enter)"
+          title={t('admin.settings.saveHint')}
         >
           <CheckIcon />
         </button>
         <button
           onClick={handleCancel}
           className="rounded-lg bg-dark-600 p-2 text-dark-300 transition-colors hover:bg-dark-500"
-          title="Отмена (Esc)"
+          title={t('admin.settings.cancelHint')}
         >
           <CloseIcon />
         </button>