fix(admin): show flag for every country code, not just hardcoded 25-36

User reported the EE (Estonia) flag rendered as plain text 'EE' on the
admin servers page. Root cause: getCountryFlag() in AdminServers.tsx
and AdminServerEdit.tsx hardcoded a 25-entry codeMap that didn't
include EE; falling through to 'return code' produced raw text.

Two other admin pages (AdminRemnawaveSquadDetail, AdminUserDetail)
had bigger 35-entry maps that did include EE — so EE worked there
but MX/AR/EG/ZA and friends still wouldn't. AdminRemnawave repeated
the same 35-entry map. AdminTrafficUsage already had the correct
algorithmic ISO→regional-indicator code but as a local duplicate of
utils/subscriptionHelpers.

Unify all six on the single algorithmic helper:

- getFlagEmoji() in utils/subscriptionHelpers.ts now:
  * accepts string | null | undefined (callers don't need to guard)
  * trims whitespace
  * validates [A-Za-z]{2} before composing regional indicators
- Each admin page now either imports getFlagEmoji directly or wraps
  it with the page's preferred fallback character (e.g. '🌍' for
  empty codes where the UI expects a placeholder).

src/pages/AdminUserDetail.tsx

@@ -24,51 +24,14 @@ import { createNumberInputHandler, toNumber } from '../utils/inputHelpers';
 import { usePermissionStore } from '../store/permissions';
 import { MessageMediaGrid } from '../components/tickets/MessageMediaGrid';
 import { linkifyText } from '../utils/linkify';
+import { getFlagEmoji } from '../utils/subscriptionHelpers';
 
 // ============ Helpers ============
 
-const getCountryFlag = (code: string | null | undefined): string => {
-  if (!code) return '';
-  const codeMap: Record<string, string> = {
-    RU: '\u{1F1F7}\u{1F1FA}',
-    US: '\u{1F1FA}\u{1F1F8}',
-    DE: '\u{1F1E9}\u{1F1EA}',
-    NL: '\u{1F1F3}\u{1F1F1}',
-    GB: '\u{1F1EC}\u{1F1E7}',
-    UK: '\u{1F1EC}\u{1F1E7}',
-    FR: '\u{1F1EB}\u{1F1F7}',
-    FI: '\u{1F1EB}\u{1F1EE}',
-    SE: '\u{1F1F8}\u{1F1EA}',
-    NO: '\u{1F1F3}\u{1F1F4}',
-    PL: '\u{1F1F5}\u{1F1F1}',
-    TR: '\u{1F1F9}\u{1F1F7}',
-    JP: '\u{1F1EF}\u{1F1F5}',
-    SG: '\u{1F1F8}\u{1F1EC}',
-    HK: '\u{1F1ED}\u{1F1F0}',
-    KR: '\u{1F1F0}\u{1F1F7}',
-    AU: '\u{1F1E6}\u{1F1FA}',
-    CA: '\u{1F1E8}\u{1F1E6}',
-    CH: '\u{1F1E8}\u{1F1ED}',
-    AT: '\u{1F1E6}\u{1F1F9}',
-    IT: '\u{1F1EE}\u{1F1F9}',
-    ES: '\u{1F1EA}\u{1F1F8}',
-    BR: '\u{1F1E7}\u{1F1F7}',
-    IN: '\u{1F1EE}\u{1F1F3}',
-    AE: '\u{1F1E6}\u{1F1EA}',
-    IL: '\u{1F1EE}\u{1F1F1}',
-    KZ: '\u{1F1F0}\u{1F1FF}',
-    UA: '\u{1F1FA}\u{1F1E6}',
-    CZ: '\u{1F1E8}\u{1F1FF}',
-    RO: '\u{1F1F7}\u{1F1F4}',
-    LV: '\u{1F1F1}\u{1F1FB}',
-    LT: '\u{1F1F1}\u{1F1F9}',
-    EE: '\u{1F1EA}\u{1F1EA}',
-    BG: '\u{1F1E7}\u{1F1EC}',
-    HU: '\u{1F1ED}\u{1F1FA}',
-    MD: '\u{1F1F2}\u{1F1E9}',
-  };
-  return codeMap[code.toUpperCase()] || code;
-};
+// Алгоритмический ISO 3166-1 alpha-2 → regional indicator (вместо хардкод-словаря,
+// который не покрывал все страны: например, EE раньше плыл сырым текстом в одних
+// местах, MX/AR/EG до сих пор отсутствуют в других). Единая точка истины в utils.
+const getCountryFlag = (code: string | null | undefined): string => getFlagEmoji(code);
 
 // ============ Icons ============