chore: remove TokenListController (#29872)

## **Description**

<!--
Write a short description of the changes included in this pull request,
also include relevant motivation and context. Have in mind the following
questions:
1. What is the reason for the change?
2. What is the improvement/solution?
-->

`TokenListController` has been removed from
`@metamask/assets-controllers` in favour of the token list being fetched
directly by dependent controllers (e.g. `TokenDetectionController`,
`TokenRatesController`). This PR removes all wiring of
`TokenListController` from the mobile app.

**Changes included:**
- Deleted `token-list-controller-init.ts` and its messenger
(`token-list-controller-messenger.ts`) along with their tests
- Deleted `useTokenListPolling` hook and its test
- Removed `TokenListController` from `Engine.ts` (instantiation, wiring,
and exported state)
- Removed `TokenListController` from `types.ts` (`MessengerClients`,
`EngineState`, `MessengerClientsToInitialize`, global action/event union
types)
- Removed `TokenListController` from `messengers/index.ts`
(`MESSENGER_FACTORIES`)
- Removed `TokenListController:stateChange` from `constants.ts`
(`BACKGROUND_STATE_CHANGE_EVENT_NAMES`)
- Removed `TOKEN_LIST_STATE_CHANGE_EVENT` constant from
`AppConstants.ts`
- Removed `useTokenListPolling` call from `AssetPollingProvider` and
`useEarnNetworkPolling`
- Removed runtime access to
`TokenListController.state.tokensChainsCache` from
`TransactionElement/utils.js`
- Removed `TokenListController.fetchTokenList` call from `AddAsset.tsx`
- Cleaned up `initial-background-state.json`, E2E fixture files
(`default-fixture.json`, `fixture-validation.ts`), and mock state files
(`Bridge/initialState.ts`, `perpsStateMock.ts`,
`other-controllers-mock.ts`, `component-view/mocks.ts`)

## **Changelog**

CHANGELOG entry: remove TokenListController

## **Related issues**

https://consensyssoftware.atlassian.net/browse/ASSETS-3181

## **Manual testing steps**

```gherkin
Feature: TokenListController removal

  Background:
    Given I am logged into MetaMask Mobile

  Scenario: NEW user imports SRP/PK with a lot of tokens (from app install)
    Tokens list and detection should work as expected
    There should be no issues loading tokens

  Scenario: EXISTING user imports SRP/PK with a lot of tokens
    Tokens list and detection should work as expected
    There should be no issues loading tokens

  Scenario: token detection still works after controller removal
    Given I am on the Wallet home screen
    And I have an account with no custom tokens

    When user navigates to Add Asset
    Then the token search screen should load without errors

    When user selects a different network
    Then no crash or error should occur

  Scenario: transaction list still displays correctly
    Given I am on the Wallet home screen
    And I have prior ERC-20 transactions

    When user navigates to the Activity tab
    Then all transactions should render without errors
    And token symbols should still appear where available
```

## **Screenshots/Recordings**

### **Before**

N/A

### **After**

https://github.com/MetaMask/metamask-mobile/actions/runs/25657693707
https://github.com/MetaMask/metamask-mobile/actions/runs/25726986329

## **Pre-merge author checklist**

- [x] I've followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask Mobile
Coding
Standards](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/CODING_GUIDELINES.md).
- [x] I've completed the PR template to the best of my ability
- [x] I've included tests if applicable
- [x] I've documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [x] I've applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

#### Performance checks (if applicable)

- [x] I've tested on Android
  - Ideally on a mid-range device; emulator is acceptable
- [x] I've tested with a power user scenario
- Use these [power-user
SRPs](https://consensyssoftware.atlassian.net/wiki/spaces/TL1/pages/edit-v2/401401446401?draftShareId=9d77e1e1-4bdc-4be1-9ebb-ccd916988d93)
to import wallets with many accounts and tokens
- [x] I've instrumented key operations with Sentry traces for production
performance metrics
- See [`trace()`](/app/util/trace.ts) for usage and
[`addToken`](/app/components/Views/AddAsset/components/AddCustomToken/AddCustomToken.tsx#L274)
for an example

## **Pre-merge reviewer checklist**

- [ ] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.

<!-- Generated with the help of the pr-description AI skill -->



<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Medium Risk**
> Medium risk because it removes `TokenListController` from Engine
wiring/state and strips related polling and fixtures, which can impact
token discovery/display paths if any remaining callsites still expect
the controller or its cached token metadata.
> 
> **Overview**
> Removes `TokenListController` integration from the app, including
Engine initialization/exported state, messenger wiring, background state
change constants, and shared type definitions.
> 
> Eliminates token-list polling (`useTokenListPolling`) and stops
calling it from `AssetPollingProvider` and `useEarnNetworkPolling`,
along with deleting the hook and its tests.
> 
> Cleans up UI callsites that depended on the controller: `AddAsset` no
longer triggers `fetchTokenList` on network change, and
`TransactionElement` no longer prefixes approval action labels using
token-list cache data. Updates/cleans fixtures and tests to reflect the
removed controller state.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
ceeb3ef. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: juanmigdr

app/components/UI/Earn/hooks/useEarnNetworkPolling.test.ts

@@ -1,5 +1,4 @@
 // Mock all the polling hooks
-jest.mock('../../../hooks/AssetPolling/useTokenListPolling', () => jest.fn());
 jest.mock('../../../hooks/AssetPolling/useTokenBalancesPolling', () =>
   jest.fn(),
 );
@@ -34,7 +33,6 @@ import { renderHookWithProvider } from '../../../../util/test/renderWithProvider
 import useEarnNetworkPolling from './useEarnNetworkPolling';
 import { RootState } from '../../../../reducers';
 import { MOCK_ACCOUNTS_CONTROLLER_STATE } from '../../../../util/test/accountsControllerTestUtils';
-import useTokenListPolling from '../../../hooks/AssetPolling/useTokenListPolling';
 import useTokenBalancesPolling from '../../../hooks/AssetPolling/useTokenBalancesPolling';
 import useCurrencyRatePolling from '../../../hooks/AssetPolling/useCurrencyRatePolling';
 import useTokenRatesPolling from '../../../hooks/AssetPolling/useTokenRatesPolling';
@@ -52,7 +50,6 @@ afterAll(() => {
 });
 
 describe('useEarnNetworkPolling', () => {
-  const mockUseTokenListPolling = jest.mocked(useTokenListPolling);
   const mockUseTokenBalancesPolling = jest.mocked(useTokenBalancesPolling);
   const mockUseCurrencyRatePolling = jest.mocked(useCurrencyRatePolling);
   const mockUseTokenRatesPolling = jest.mocked(useTokenRatesPolling);
@@ -140,9 +137,6 @@ describe('useEarnNetworkPolling', () => {
       state: mockState,
     });
 
-    expect(mockUseTokenListPolling).toHaveBeenCalledWith({
-      chainIds: expect.any(Array),
-    });
     expect(mockUseTokenBalancesPolling).toHaveBeenCalledWith({
       chainIds: expect.any(Array),
     });
@@ -164,9 +158,6 @@ describe('useEarnNetworkPolling', () => {
     });
 
     // Initially called with empty arrays
-    expect(mockUseTokenListPolling).toHaveBeenCalledWith({
-      chainIds: [],
-    });
     expect(mockUseTokenBalancesPolling).toHaveBeenCalledWith({
       chainIds: [],
     });
@@ -367,7 +358,6 @@ describe('useEarnNetworkPolling', () => {
     rerender({});
 
     // All polling hooks should be called again
-    expect(mockUseTokenListPolling).toHaveBeenCalled();
     expect(mockUseTokenBalancesPolling).toHaveBeenCalled();
     expect(mockUseCurrencyRatePolling).toHaveBeenCalled();
     expect(mockUseTokenRatesPolling).toHaveBeenCalled();

app/components/UI/Earn/hooks/useEarnNetworkPolling.ts

@@ -10,7 +10,6 @@ import { selectUseTokenDetection } from '../../../../selectors/preferencesContro
 import useCurrencyRatePolling from '../../../hooks/AssetPolling/useCurrencyRatePolling';
 import useTokenBalancesPolling from '../../../hooks/AssetPolling/useTokenBalancesPolling';
 import useTokenDetectionPolling from '../../../hooks/AssetPolling/useTokenDetectionPolling';
-import useTokenListPolling from '../../../hooks/AssetPolling/useTokenListPolling';
 import useTokenRatesPolling from '../../../hooks/AssetPolling/useTokenRatesPolling';
 import { RootState } from '../../BasicFunctionality/BasicFunctionalityModal/BasicFunctionalityModal.test';
 import { EVM_SCOPE } from '../constants/networks';
@@ -61,7 +60,6 @@ export const useEarnNetworkPolling = () => {
   );
   const [lendingChainIds, setLendingChainIds] = useState<Hex[]>([]);
 
-  useTokenListPolling({ chainIds: lendingChainIds });
   useTokenBalancesPolling({ chainIds: lendingChainIds });
   useCurrencyRatePolling({ chainIds: lendingChainIds });
   useTokenRatesPolling({ chainIds: lendingChainIds });

app/components/UI/TransactionElement/utils.js

@@ -839,15 +839,7 @@ function decodeConfirmTx(args) {
 
   const renderFrom = renderFullAddress(from);
   const renderTo = renderFullAddress(to);
-  const chainId = txChainId;
-
-  const tokenList =
-    Engine.context.TokenListController.state.tokensChainsCache?.[chainId]
-      ?.data || [];
-  let symbol;
-  if (renderTo in tokenList) {
-    symbol = tokenList[renderTo].symbol;
-  }
+
   let transactionType;
   if (actionKey === strings('transactions.approve'))
     transactionType = TRANSACTION_TYPES.APPROVE;
@@ -876,7 +868,7 @@ function decodeConfirmTx(args) {
   const transactionElement = {
     renderTo,
     renderFrom,
-    actionKey: symbol ? `${symbol} ${actionKey}` : actionKey,
+    actionKey,
     value: renderTotalEth,
     fiatValue: renderTotalEthFiat,
     transactionType,

app/components/Views/AddAsset/AddAsset.tsx

@@ -10,9 +10,7 @@ import { useNavigation } from '@react-navigation/native';
 import { useParams } from '../../../util/navigation/navUtils';
 import { BottomSheetRef } from '../../../component-library/components/BottomSheets/BottomSheet';
 import { Hex } from '@metamask/utils';
-import Engine from '../../../core/Engine';
 import { SupportedCaipChainId } from '@metamask/multichain-network-controller';
-import { isNonEvmChainId } from '../../../core/Multichain/utils';
 import { useNetworkEnablement } from '../../hooks/useNetworkEnablement/useNetworkEnablement';
 import HeaderCompactStandard from '../../../component-library/components-temp/HeaderCompactStandard';
 import NetworkListBottomSheet from './components/NetworkListBottomSheet/NetworkListBottomSheet';
@@ -56,9 +54,6 @@ const AddAsset = () => {
         selectedNetwork={selectedNetwork}
         setSelectedNetwork={async (network) => {
           setSelectedNetwork(network);
-          if (!isNonEvmChainId(network)) {
-            Engine.context.TokenListController.fetchTokenList(network as Hex);
-          }
         }}
         setOpenNetworkSelector={setOpenNetworkSelector}
         sheetRef={sheetRef}

app/components/hooks/AssetPolling/AssetPollingProvider.test.tsx

@@ -4,7 +4,6 @@ import { useSelector } from 'react-redux';
 import useCurrencyRatePolling from './useCurrencyRatePolling';
 import useTokenRatesPolling from './useTokenRatesPolling';
 import useTokenDetectionPolling from './useTokenDetectionPolling';
-import useTokenListPolling from './useTokenListPolling';
 import useTokenBalancesPolling from './useTokenBalancesPolling';
 
 import { AssetPollingProvider } from './AssetPollingProvider';
@@ -18,7 +17,6 @@ jest.mock('react-redux', () => ({
 jest.mock('./useCurrencyRatePolling', () => jest.fn());
 jest.mock('./useTokenRatesPolling', () => jest.fn());
 jest.mock('./useTokenDetectionPolling', () => jest.fn());
-jest.mock('./useTokenListPolling', () => jest.fn());
 jest.mock('./useTokenBalancesPolling', () => jest.fn());
 jest.mock('./useAccountTrackerPolling', () => jest.fn());
 jest.mock('./useMultichainAssetsRatePolling', () => jest.fn());
@@ -34,7 +32,6 @@ describe('AssetPollingProvider', () => {
   const mockUseCurrencyRatePolling = jest.mocked(useCurrencyRatePolling);
   const mockUseTokenRatesPolling = jest.mocked(useTokenRatesPolling);
   const mockUseTokenDetectionPolling = jest.mocked(useTokenDetectionPolling);
-  const mockUseTokenListPolling = jest.mocked(useTokenListPolling);
   const mockUseTokenBalancesPolling = jest.mocked(useTokenBalancesPolling);
   const mockUseMultichainAssetsRatePolling = jest.mocked(
     useMultichainAssetsRatePolling,
@@ -57,7 +54,6 @@ describe('AssetPollingProvider', () => {
     expect(mockUseCurrencyRatePolling).toHaveBeenCalledWith(undefined);
     expect(mockUseTokenRatesPolling).toHaveBeenCalledWith(undefined);
     expect(mockUseTokenDetectionPolling).toHaveBeenCalledWith(undefined);
-    expect(mockUseTokenListPolling).toHaveBeenCalledWith(undefined);
     expect(mockUseTokenBalancesPolling).toHaveBeenCalledWith(undefined);
     expect(mockUseMultichainAssetsRatePolling).toHaveBeenCalledWith({
       accountId: 'mock-account-id',
@@ -85,10 +81,6 @@ describe('AssetPollingProvider', () => {
       address: '0x1234567890abcdef',
     });
 
-    expect(mockUseTokenListPolling).toHaveBeenCalledWith({
-      chainIds: CHAIN_IDS_MOCK,
-    });
-
     expect(mockUseTokenBalancesPolling).toHaveBeenCalledWith({
       chainIds: CHAIN_IDS_MOCK,
     });

app/components/hooks/AssetPolling/AssetPollingProvider.tsx

@@ -4,7 +4,6 @@ import { useSelector } from 'react-redux';
 import useCurrencyRatePolling from './useCurrencyRatePolling';
 import useTokenRatesPolling from './useTokenRatesPolling';
 import useTokenDetectionPolling from './useTokenDetectionPolling';
-import useTokenListPolling from './useTokenListPolling';
 import useTokenBalancesPolling from './useTokenBalancesPolling';
 import useMultichainAssetsRatePolling from './useMultichainAssetsRatePolling';
 import { selectSelectedInternalAccount } from '../../../selectors/accountsController';
@@ -29,7 +28,6 @@ export const AssetPollingProvider = memo(
     useCurrencyRatePolling(chainParams);
     useTokenRatesPolling(chainParams);
     useTokenDetectionPolling(tokenDetectionParams);
-    useTokenListPolling(chainParams);
     useTokenBalancesPolling(chainParams);
 
     useMultichainAssetsRatePolling(