refactor(converter): shared page layout + reusable conversion logic/UI

Pages:
- add WalletLayout route (WalletHeader + main + Footer via <Outlet/>),
  wrap converter/swap/bridge/transactions; thin pages, drop duplicated shell CSS
- extract SwapBridgeTabs shared between swap/bridge pages

Converter reuse (FSD layers, no widget->widget imports):
- move commission tiers to entities/commission (+ CommissionTable ui)
- shared calc hook features/payment/model/useCurrencyConversion;
  useConverterSection becomes thin wrapper; HomePage Converter reuses it
- move ConvertField/DirectionSwapButton to shared/ui; delete dead useConverter

Tooling:
- add eslint.config.js (ESLint 9 flat config); fix no-explicit-any in WalletPage

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/shared/ui/ConvertField/ConvertField.tsx

@@ -0,0 +1,44 @@
+import styles from './ConvertField.module.css'
+
+export type Currency = 'USDT' | 'RUB'
+
+export interface ConvertFieldData {
+  value: string
+  currency: Currency
+  onChange?: (raw: string) => void
+  error?: string
+}
+
+interface Props extends ConvertFieldData {
+  label?: string
+  compact?: boolean
+}
+
+export function ConvertField({ label, value, currency, onChange, error, compact }: Props) {
+  const readOnly = !onChange
+
+  return (
+    <div className={compact ? `${styles.field} ${styles.compact}` : styles.field}>
+      {label && <div className={styles.fieldLabel}>{label}</div>}
+      <div className={styles.fieldInput}>
+        <input
+          type="text"
+          value={value}
+          onChange={onChange ? (e) => onChange(e.target.value) : undefined}
+          readOnly={readOnly}
+          placeholder="0"
+          inputMode={readOnly ? undefined : 'decimal'}
+        />
+        <div className={styles.currency}>
+          <span
+            className={`${styles.currencyIcon} ${currency === 'USDT' ? styles.currencyUsdt : styles.currencyRub}`}
+          >
+            {currency === 'USDT' ? '₮' : '₽'}
+          </span>
+          {currency}
+        </div>
+      </div>
+      {error && <div className={styles.fieldError}>{error}</div>}
+    </div>
+  )
+}