…30711)

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## **Description**

This attempts to fix what was intended to be fixed in PR #30419 but for
some reason that PR did not work - to ensure that a source token is used
when opening an Ondo swap from Rewards. It also updates the button text
to say "Trade now" instead of "Open Position."

## **Changelog**

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CHANGELOG entry: null

## **Related issues**

Fixes: n/a

## **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]
```

## **Screenshots/Recordings**

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### **Before**

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### **After**

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## **Pre-merge author checklist**

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- [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).
- [x] I've completed the PR template to the best of my ability
- [x] I've included tests if applicable
- [x] I've documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [x] I've applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-mobile/blob/main/.github/guidelines/LABELING_GUIDELINES.md)).
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](https://consensyssoftware.atlassian.net/wiki/spaces/TL1/pages/edit-v2/401401446401?draftShareId=9d77e1e1-4bdc-4be1-9ebb-ccd916988d93)
to import wallets with many accounts and tokens
- [ ] I've instrumented key operations with Sentry traces for production
performance metrics
- See [`trace()`](/app/util/trace.ts) for usage and
[`addToken`](/app/components/Views/AddAsset/components/AddCustomToken/AddCustomToken.tsx#L274)
for an example

For performance guidelines and tooling, see the [Performance
Guide](https://consensyssoftware.atlassian.net/wiki/spaces/TL1/pages/400085549067/Performance+Guide+for+Engineers).

## **Pre-merge reviewer checklist**

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- [ ] I've manually tested the PR (e.g. pull and build branch, run the
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- [ ] 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.

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> Copy and Rewards swap prefill logic only; changes are localized with
new unit tests and no auth or payment impact.
> 
> **Overview**
> Renames the opted-in, no-positions Ondo campaign CTA from **Open
Position** to **Trade now** via `rewards.campaign_details.open_position`
in `en.json`, with matching test and comment updates.
> 
> Fixes **open position** swaps from Rewards by resolving default source
tokens through a new `getOndoOpenPositionSourceToken` helper: chain
defaults are keyed by hex (`0x1` → USDC, `0x38` → USDT) instead of
CAIP-only map lookups, and the helper accepts hex or `eip155:` chain IDs
(including after-hours confirm). USDY balance preference is unchanged;
tests cover BNB/USDT and the helper edge cases.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
be88b88. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->