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>

eslint.config.js

@@ -0,0 +1,28 @@
+import js from '@eslint/js'
+import globals from 'globals'
+import reactHooks from 'eslint-plugin-react-hooks'
+import reactRefresh from 'eslint-plugin-react-refresh'
+import tseslint from 'typescript-eslint'
+
+export default tseslint.config(
+  { ignores: ['dist'] },
+  {
+    extends: [js.configs.recommended, ...tseslint.configs.recommended],
+    files: ['**/*.{ts,tsx}'],
+    languageOptions: {
+      ecmaVersion: 2020,
+      globals: globals.browser,
+    },
+    plugins: {
+      'react-hooks': reactHooks,
+      'react-refresh': reactRefresh,
+    },
+    rules: {
+      ...reactHooks.configs.recommended.rules,
+      'react-refresh/only-export-components': [
+        'warn',
+        { allowConstantExport: true },
+      ],
+    },
+  },
+)