fix: swap activity fee label paid by metamask

[maxime-oe]

Description

Changelog

CHANGELOG entry: adds "Paid by MetaMask" on Activity "Total gas fee" row when the tx was a gas-sponsored swap.

Related issues

Fixes: #27246

Manual testing steps

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]

1. Select Monad or SEI network (or any gas-sponsored network).
2. Select the in-app Swap feature (or "buy/sell") selecting tokens from the same network.
3. Perform the swap - "Paid by MetaMask".
4. Once completed, click on the transaction item in the Activity tab.
5. Observe content of the Transaction Detail view.

Screenshots/Recordings

Before

Showing a MON gas fee amount (zero).

After

Showing the "Paid by MetaMask" label.

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Mobile Coding Standards.
• I've completed the PR template to the best of my ability
• I've included tests if applicable
• I've documented my code using JSDoc format if applicable
• I've applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

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.

---

Note

Low Risk
Small UI-only change gated by existing isGasFeeSponsored flag; low risk aside from potential styling/layout regressions in the transaction details view.

Overview
Updates the Bridge/Swap transaction details screen to display a green Paid by MetaMask tag in the Total gas fee row when evmTxMeta.isGasFeeSponsored is true, instead of showing a (typically zero) native gas amount.

Introduces a small reusable PaidByMetaMask component using TagColored (with testID: paid-by-metamask) and keeps the prior fee amount rendering for non-sponsored transactions.

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[github-actions]

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[github-actions]

🔍 Smart E2E Test Selection

• Selected E2E tags: SmokeTrade, SmokeConfirmations
• Selected Performance tags: None (no tests recommended)
• Risk Level: medium
• AI Confidence: 85%

click to see 🤖 AI reasoning details

E2E Test Selection:
The change is in app/components/UI/Bridge/components/TransactionDetails/TransactionDetails.tsx, which is part of the Bridge flow UI under the Trade feature. Bridge flows are explicitly covered by SmokeTrade (token swaps and cross-chain bridging). Since SmokeTrade requires transaction confirmations as part of swap/bridge flows, SmokeConfirmations must also be selected per tag dependency rules.

This change affects transaction detail rendering within the bridge flow, which could impact:

• Bridge execution UI
• Transaction detail display during/after bridge
• Integration with confirmation and activity flows

There are no changes to controllers, Engine, network management, identity, snaps, card, perps, predictions, or multi-chain APIs. Therefore, other tags (SmokeWalletPlatform, SmokeNetworkAbstractions, SmokeNetworkExpansion, SmokeMultiChainAPI, SmokeAccounts, SmokeIdentity, SmokeCard, SmokePerps, SmokePredictions, FlaskBuildTests) are not required.

The impact is scoped to a Trade subcomponent UI, with moderate risk because it is user-facing in a financial transaction flow.

Performance Test Selection:
The change is limited to a Bridge TransactionDetails UI component. There is no indication of changes to rendering-heavy lists, account selectors, asset loading logic, controller performance, app launch, onboarding, or swap quote fetching. Therefore, no dedicated performance test tags (e.g., @PerformanceSwaps, @PerformanceAssetLoading) are required.

View GitHub Actions results

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

✅ E2E Fixture Validation — Schema is up to date
11 value mismatches detected (expected — fixture represents an existing user).
View details

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Cursor Bugbot has reviewed your changes and found 1 potential issue.

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