Description

Adds navigateToRampBuy as a shared imperative entry point that mirrors useRampNavigation.goToBuy (UB2 BuildQuote / token selection, eligibility modals, V1 deposit vs aggregator, override modes). Refactors useRampNavigation to delegate to that helper. Introduces app/components/UI/Ramp/navigation.ts as a small barrel for ramp navigation exports. Includes unit tests for navigateToRampBuy.

Follow-up (not in this PR): phased work such as NativeFlow hoist, sell-only aggregator routing, and removing Deposit-only paths is out of scope until those changes exist in the tree.

Changelog

CHANGELOG entry: null

Related issues

Fixes: N/A

Manual testing steps

Feature: Ramp buy navigation helper

  Scenario: spot-check existing ramp buy entry points
    Given a dev build with ramps enabled
    When the user opens buy from an existing ramp entry that uses useRampNavigation
    Then routing behavior matches pre-refactor UB2/V1 paths

Screenshots/Recordings

N/A (internal refactor; no intentional UI change).

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.

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.