## **Description**

Cherry-pick #26015 into `7.65.0` release.

Applies a Yarn patch to `@metamask/transaction-pay-controller` instead
of bumping controller version to avoid unrelated changes.

## **Changelog**

CHANGELOG entry: null

## **Related issues**

Fixes: #25972 

## **Manual testing steps**

## **Screenshots/Recordings**

## **Pre-merge author checklist**

- [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.

## **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.

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Medium Risk**
> Touches transaction-pay quoting/totals and stablecoin detection, which
can affect displayed costs and max-amount behavior across networks;
mitigated by being a targeted patch and limited app-side changes.
> 
> **Overview**
> Fixes transaction pay quote/total calculations by **patching
`@metamask/transaction-pay-controller` 12.1.0** rather than bumping the
dependency.
> 
> The patch centralizes a multi-chain `STABLECOINS` list, treats
stablecoins as $1 in token fiat-rate logic, and changes `targetAmount`
across quotes/totals to be a `FiatValue` summed via `sumFiat` (avoiding
incorrect max/totals math). Relay quote normalization now accounts for
`fees.subsidized` by zeroing provider fees when subsidized and
optionally including the subsidized amount in the computed target fiat
value; Bridge normalization aligns `targetAmount` to fiat-only as well.
> 
> On the mobile side, `useTokenFiatRates` now uses a stablecoin
allowlist (Mainnet/Arbitrum/Linea/Polygon) to return a fixed USD rate of
`1`, and the related unit test is generalized accordingly. The
Transaction Pay controller messenger drops the unused
`TokenListController:getState` action, and `package.json`/`yarn.lock`
are updated to consume the patched controller via Yarn’s `patch:`
protocol.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
61d257e. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->