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## **Description**

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Write a short description of the changes included in this pull request,
also include relevant motivation and context. Have in mind the following
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1. What is the reason for the change?
2. What is the improvement/solution?
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This PR establishes a pattern for splitting out controllers from the
main `Engine.ts` file, which provides the following benefits
- Reduce friction regarding code ownership especially during reviews
(this is the main purpose of this effort)
- Easier to manage, test, and handling controller initialization
failures


The POC here applies to the `AccountsController` initialization logic,
which has been mostly abstracted out into `AccountsController`
directory. This pattern should be applicable to other controllers in the
Engine file as well.

This pattern also enables us to redirect users to vault recovery in the
event of controller initialization failures and should reduce the
chances of users being "bricked". These changes may be introduced in
future interations

## **Related issues**

Fixes: #12184 

## **Manual testing steps**

The changes should not affect app behavior
- Run the app as usual
- Ensure that everything behaves as usual (Auth, dapp connections,
navigation, etc)

## **Screenshots/Recordings**

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before and after of your change. -->

### **Before**

<!-- [screenshots/recordings] -->

### **After**

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App still runs normally


https://github.com/user-attachments/assets/dc7fc017-1a26-4681-b84a-e04c63952281


## **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**

- [x] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [x] 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.