feat: adds skeleton loader for quote fetching (#27174)

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## **Description**

Adds a skeleton loader during quote fetching in the swaps experience.

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CHANGELOG entry: improves quote loading UI

## **Related issues**

Fixes: null

## **Manual testing steps**

```gherkin
Feature: my feature name

  Scenario: user [verb for user action]
    Given [describe expected initial app state]

    When user [verb for user action]
    Then [describe expected outcome]
```

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### **After**

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## **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).
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- [ ] I've manually tested the PR (e.g. pull and build branch, run the
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in the ticket it closes and includes the necessary testing evidence such
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<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> Low risk UI/test-only change that adds deterministic `testID`s and a
small unit test for the quote details loading skeleton; no business
logic or data flow changes.
> 
> **Overview**
> Adds a dedicated `QuoteDetailsCardSkeleton` loading state with per-row
`testID`s and re-exports it from `QuoteDetailsCard/index.ts`.
> 
> Updates `QuoteDetailsCard.test.tsx` to cover the skeleton, asserting
the `QUOTE_DETAILS_SKELETON` container renders and contains **four**
loading rows.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
4309445. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: ghgoodreau

app/components/UI/Bridge/components/QuoteDetailsCard/QuoteDetailsCard.test.tsx

@@ -3,6 +3,7 @@ import '../../_mocks_/initialState';
 import { fireEvent, waitFor } from '@testing-library/react-native';
 import { renderScreen } from '../../../../../util/test/renderWithProvider';
 import QuoteDetailsCard from './QuoteDetailsCard';
+import QuoteDetailsCardSkeleton from './QuoteDetailsCardSkeleton';
 import { strings } from '../../../../../../locales/i18n';
 import Routes from '../../../../../constants/navigation/Routes';
 import mockQuotes from '../../_mocks_/mock-quotes-sol-sol.json';
@@ -11,6 +12,7 @@ import { createBridgeTestState } from '../../testUtils';
 import { useBridgeQuoteData } from '../../hooks/useBridgeQuoteData';
 import { MetaMetricsSwapsEventSource } from '@metamask/bridge-controller';
 import { PriceImpactModalType } from '../PriceImpactModal/constants';
+import { BridgeViewSelectorsIDs } from '../../Views/BridgeView/BridgeView.testIds';
 
 jest.mock(
   '../../../../../animations/rewards_icon_animations.riv',
@@ -273,11 +275,28 @@ const QuoteDetailsCardTestScreen = () => (
   />
 );
 
+const QuoteDetailsCardSkeletonTestScreen = () => <QuoteDetailsCardSkeleton />;
+
 describe('QuoteDetailsCard', () => {
   beforeEach(() => {
     jest.clearAllMocks();
   });
 
+  it('renders a four-row loading skeleton', () => {
+    const { getByTestId, getAllByTestId } = renderScreen(
+      QuoteDetailsCardSkeletonTestScreen,
+      {
+        name: Routes.BRIDGE.ROOT,
+      },
+      { state: testState },
+    );
+
+    expect(
+      getByTestId(BridgeViewSelectorsIDs.QUOTE_DETAILS_SKELETON),
+    ).toBeDefined();
+    expect(getAllByTestId('quote-details-card-loading-row')).toHaveLength(4);
+  });
+
   it('renders initial state', () => {
     const { toJSON } = renderScreen(
       QuoteDetailsCardTestScreen,

app/components/UI/Bridge/components/QuoteDetailsCard/QuoteDetailsCardSkeleton.tsx

@@ -23,6 +23,7 @@ const QuoteDetailsCardSkeleton = () => (
     {ROWS.map(([left, right], i) => (
       <Box
         key={i}
+        testID="quote-details-card-loading-row"
         flexDirection={BoxFlexDirection.Row}
         justifyContent={BoxJustifyContent.Between}
         alignItems={BoxAlignItems.Center}

app/components/UI/Bridge/components/QuoteDetailsCard/index.ts

@@ -1 +1,2 @@
 export { default } from './QuoteDetailsCard';
+export { default as QuoteDetailsCardSkeleton } from './QuoteDetailsCardSkeleton';