…139] cp-7.69.0 (#27139)

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## **Description**

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also include relevant motivation and context. Have in mind the following
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2. What is the improvement/solution?
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Fix branch deeplinks not working with the X (Twitter) app by adding a
`$deeplink_path` param in branch.io and consuming it in MetaMask Mobile.

### Context

- Platform: happens only on iOS. Android behaves differently (no
Deepview in our flow).
- User taps a t.co link in X (Twitter) → redirects to
https://metamask.app.link/1WkF6GmE40b (which is a link generated by
X/Branch.io on Tweet posting) → Branch Deepview is shown → user taps
“Get the app” → opens MetaMask via Universal Link:
https://metamask-alternate.app.link/1WkF6GmE40b?__branch_flow_type=viewapp&__branch_flow_id=...&__branch_mobile_deepview_type=1.
- Issue: The app opens correctly, but in-app we show a “page not found”
(404). So the OS and Branch open the app, but we don’t know which in-app
route corresponds to link ID 1WkF6GmE40b.

### What we found

1. No resolved URI from the SDK
- The Branch iOS SDK (and react-native-branch) give us:
- The raw URL that opened the app (e.g.
https://metamask-alternate.app.link/1WkF6GmE40b?...), and
- The params from the session (e.g. from getLatestReferringParams() /
subscribe callback).
- The SDK does not build a custom deeplink URI (e.g. metamask://swap)
from link data; it only returns the params. So we have to do routing
ourselves.

2. Implemented fix:
- Added a $deeplink_path in Branch deeplinks (this must be added to
every existing and future deeplinks that we want to post on X)
- Read it from the params and build our deeplink ourselves (e.g.
metamask://${params.$deeplink_path}) and then route inside the app.

## **Changelog**

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`CHANGELOG entry: Fixed a bug that was causing some NFTs to flicker`

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CHANGELOG entry: Fixed a bug that was causing deeplinks opened from X
app to fail

## **Related issues**

Fixes: https://consensyssoftware.atlassian.net/browse/GE-139
Fixes: #27140

## **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 and after of your change. -->

### **Before**

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### **After**

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## **Pre-merge author checklist**

- [ ] 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).
- [ ] 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](https://jsdoc.app/) format
if applicable
- [ ] 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 deeplink routing/host allowlists and Branch handling on app
start, which can affect navigation from external links, but the change
is narrowly scoped and covered by new unit tests.
> 
> **Overview**
> Fixes Branch short-link universal links (notably from X on iOS) by
introducing `rewriteBranchUri`, which converts
`metamask-alternate.app.link/<id>` URLs into
`https://link.metamask.io/<$deeplink_path>` while preserving query
params.
> 
> `DeeplinkManager.start()` now applies this rewrite for both cold-start
Branch params (`~referring_link`) and `branch.subscribe` events,
replacing the prior `getLatestReferringParams` fallback logic.
> 
> Adds `MM_UNIVERSAL_LINK_HOST_ALTERNATE`
(`metamask-alternate.app.link`) and includes it in universal-link host
validation (`handleUniversalLink`) and MetaMask-host detection
(`util/deeplinks`), with new tests covering rewrite and routing
behavior.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
de4e3dc. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->