chore(onboarding): remove dead WhatsNewModal feature

[wachunei]

Description

The What's New modal (WhatsNewModal) is no longer shown to users. The auto-show hook was never wired up, and the Wallet screen only retained a no-op effect with a stale comment. This PR removes the dead modal feature entirely — component, hook, navigation route, storage key, locales, assets, tests, and related fixtures — to reduce maintenance surface and avoid investing in performance fixes for unused UI (see #31279).

Changelog

CHANGELOG entry: null

Related issues

Fixes: #31279

Manual testing steps

Feature: Wallet loads without What's New modal

  Scenario: user opens the wallet after upgrade
    Given the user has an existing wallet and is on the home screen

    When the user navigates to the Wallet tab
    Then no What's New modal appears
    And the wallet renders normally

Screenshots/Recordings

Before

N/A — removal of dead code with no user-visible UI.

After

N/A — removal of dead code with no user-visible UI.

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.

Performance checks (if applicable)

• I've tested on Android
  • Ideally on a mid-range device; emulator is acceptable
• I've tested with a power user scenario
  • Use these power-user SRPs to import wallets with many accounts and tokens
• I've instrumented key operations with Sentry traces for production performance metrics
  • See trace() for usage and addToken for an example

For performance guidelines and tooling, see the Performance Guide.

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
Dead-code removal with no user-visible behavior change; navigation and Wallet paths are simplified without touching auth, payments, or data handling.

Overview
Removes the unused What's New modal flow from navigation and onboarding: drops Routes.MODAL.WHATS_NEW, unregisters the screen from RootModalFlow in App.tsx, and deletes useCheckWhatsNewModal plus shouldShowWhatsNewModal from app/util/onboarding.

Cleans up Wallet by removing a stale effect and related network-onboarding/usePrevious wiring that no longer drove any UI. Test and fixture updates drop WhatsNew route assertions, the hook tests, E2E WhatsNewModal page object, and @MetaMask:WhatsNewAppVersionSeen from default async state.

^{Reviewed by Cursor Bugbot for commit 733e053. Bugbot is set up for automated code reviews on this repo. Configure here.}

[cursor]

Current version of PR was reviewed by /review-bugbot on Jun 19, 13:23 GMT-4. It flagged 0 findings.

^{Bugbot on commit 6431082 is skipped.}

[github-actions]

🔍 Smart E2E Test Selection

• Selected E2E tags: SmokeAccounts, SmokeConfirmations, SmokeIdentity, SmokeNetworkAbstractions, SmokeNetworkExpansion, SmokeSwap, SmokeStake, SmokeWalletPlatform, SmokeMoney, SmokePerps, SmokeMultiChainAPI, SmokePredictions, SmokeSeedlessOnboarding, SmokeBrowser, SmokeSnaps
• Selected Performance tags: None (no tests recommended)
• Risk Level: high
• AI Confidence: 100%

click to see 🤖 AI reasoning details

E2E Test Selection:
Hard rule (global-infrastructure-change): Global infrastructure changed: app/components/hooks/useCheckWhatsNewModal/index.ts, app/components/hooks/useCheckWhatsNewModal/useCheckWhatsNewModal.test.ts, app/components/hooks/useCheckWhatsNewModal/useCheckWhatsNewModal.ts. Running all tests.

Performance Test Selection:
The changes are purely a removal of the WhatsNew modal feature - deleting a hook, utility function, navigation route, and page object. There are no changes to performance-sensitive flows like app launch, login, asset loading, swaps, or onboarding performance. The Wallet component cleanup removes a dead useEffect (no performance impact). No performance test tags are warranted.

View GitHub Actions results

[sonarqubecloud]

Quality Gate passed

Issues
2 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