fix(account-tree-controller): address group names consistency bug (#6601)

## Explanation

**CRITICAL FIX**: Resolves a severe multi-wallet account naming bug that
caused duplicate, inconsistent, and confusing account group names across
different seed phrases (SRPs).

### Current Problem
Users importing multiple seed phrases experienced catastrophic naming
issues:
- **Duplicate names**: Multiple "Account 2", "Account 3" within the same
wallet
- **Missing "Account 1"**: Some wallets would start at "Account 2" 
- **Cross-wallet confusion**: Second SRP incorrectly showing "Account 3"
when it should be "Account 1"
- **Inconsistent after restart**: Names would change unpredictably on
app restart

### Root Cause
The account group naming logic had critical flaws:

1. **Broken alphabetical sorting**: Used
`Object.keys(wallet.groups).sort()` which caused conflicts and
duplicates in multi-wallet scenarios
2. **Unsafe entropy access**: Could throw TypeError when accessing
`group.metadata.entropy.groupIndex` without null checks
3. **Negative index bug**: Empty wallets would get `-1` index, causing
invalid "Account 0" names

### Solution
Implemented a robust fix with comprehensive improvements:

1. **Per-wallet sequential numbering**: Each wallet maintains
independent "Account 1", "Account 2", etc. numbering with dynamic
pattern detection that works with any naming convention ("Account N",
"Imported Account N", etc.)
2. **Smart conflict resolution**: Universal conflict detection with
`while` loop that finds next available unique name, handles user
renames, and ensures unique sequential names
3. **Entropy-aware indexing**: For multichain groups, prioritizes actual
`groupIndex` from entropy metadata when available with safe null checks
4. **Starting point optimization**: Begins name checking at
`wallet.groups.length` to minimize iterations and improve efficiency
5. **AutoHandleConflict integration**: Added optional
`autoHandleConflict` parameter to `setAccountGroupName()` for automated
conflict resolution with suffix generation (`"Account 1 (2)"`, `"Account
1 (3)"`, etc.) - ready for Backup & Sync integration

## References

Fixes: 
- [MUL-835](https://consensyssoftware.atlassian.net/browse/MUL-835)
- [MUL-826](https://consensyssoftware.atlassian.net/browse/MUL-826)

## Checklist

- [x] I've updated the test suite for new or updated code as appropriate
- [x] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [x] I've communicated my changes to consumers by updating changelogs
for packages I've changed, highlighting breaking changes as necessary
- [x] I've prepared draft pull requests for clients and consumer
packages to resolve any breaking changes

[MUL-835]:
https://consensyssoftware.atlassian.net/browse/MUL-835?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

---------

Co-authored-by: Charly Chevalier <charly.chevalier@consensys.net>

Author: fabiobozzo

packages/account-tree-controller/CHANGELOG.md

@@ -7,6 +7,21 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Add `autoHandleConflict` parameter to `setAccountGroupName` method for automatic conflict resolution with suffix generation ([#6601](https://github.com/MetaMask/core/pull/6601))
+
+### Changed
+
+- Computed names (inherited from previous existing accounts) is disabled temporarily ([#6601](https://github.com/MetaMask/core/pull/6601))
+  - They do interfere with the naming mechanism, so we disable them temporarily in favor of the new per-wallet sequential naming.
+
+### Fixed
+
+- Fix multi-wallet account group naming inconsistencies and duplicates ([#6601](https://github.com/MetaMask/core/pull/6601))
+  - Implement proper per-wallet sequential numbering with highest account index parsing.
+  - Add name persistence during group initialization to ensure consistency across app restarts.
+
 ## [0.17.0]
 
 ### Changed
@@ -38,10 +53,6 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Bump `@metamask/utils` from `^11.4.2` to `^11.8.0` ([#6588](https://github.com/MetaMask/core/pull/6588))
 - Bump `@metamask/base-controller` from `^8.3.0` to `^8.4.0` ([#6632](https://github.com/MetaMask/core/pull/6632))
 
-### Removed
-
-- Remove use of `:getSelectedAccount` action ([#6608](https://github.com/MetaMask/core/pull/6608))
-
 ## [0.15.1]
 
 ### Fixed