fix(perps): enable live PnL in perps position card

[michalconsensys]

Description

This PR enables live PnL (Profit and Loss) updates in the Perps Market Tabs by subscribing to real-time price updates from the WebSocket stream.

Changelog

CHANGELOG entry: Fixed live PnL updates in Perps market tabs to reflect real-time price changes

Related issues

Fixes: https://consensyssoftware.atlassian.net/browse/TAT-1946

Manual testing steps

Feature: Live PnL updates in Perps Market Tabs

  Scenario: user views position with live PnL updates
    Given user has an open perpetual position
    And user is on the Perps Market Tabs screen
    
    When market price changes
    Then the unrealized PnL and ROE values update in real-time
    And the position card reflects current market conditions

Screenshots/Recordings

Before

After

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

Enable live PnL by passing useLivePnl: true to usePerpsLivePositions within PerpsMarketTabs.tsx.

^{Written by Cursor Bugbot for commit ff91917. This will update automatically on new commits. Configure here.}

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
1 Accepted issue

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[cursor]

Bug: Unthrottled Live PnL impacts performance.

Enabling useLivePnl: true with throttleMs: 0 causes the component to re-render on every WebSocket price tick, potentially degrading performance. Other components using live PnL (like PerpsPositionsView) throttle updates to 1000ms. Consider adding throttling to balance real-time updates with performance, especially since the component already uses memoization to isolate price updates in StatisticsTabContent.