chore: update tooling (same as core) (#517)

Using new tooling (same as `core`).

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Medium Risk**
> Tooling changes upgrade ESLint to v9 and replace Prettier-driven misc
linting with `oxfmt`, which can change lint/format outputs and CI
behavior across the monorepo. Functional code changes are minimal
(mostly import/type-only cleanups), but review should confirm the new
lint/suppression setup matches current expectations.
> 
> **Overview**
> Switches from legacy `.eslintrc.js` to an ESLint v9 flat config in
`eslint.config.mjs`, including `projectService` TypeScript parsing,
targeted overrides, and a new `eslint-suppressions.json` for managed
rule suppressions.
> 
> Adopts `oxfmt` for misc formatting (`.oxfmtrc.json`) and updates root
scripts (e.g., `lint:*`, `create-release-branch`, build cleanup), while
upgrading core tooling deps (ESLint 9, Prettier 3,
`@metamask/eslint-config` v15) and dropping `syncpack`-based dependency
mismatch checks.
> 
> Across packages, normalizes `package.json` publish metadata (`files`,
`main`/`types`, `publishConfig`, `tsd` config) and applies mostly
non-functional code churn (import ordering, `import type`, removing
inline eslint-disable comments, small readability tweaks).
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
32dfc96. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

---------

Co-authored-by: Daniel Rocha <68558152+danroc@users.noreply.github.com>

Author: ccharly

.eslintrc.js

@@ -0,0 +1,22 @@
+{
+  "$schema": "./node_modules/oxfmt/configuration_schema.json",
+  "printWidth": 80,
+  "quoteProps": "as-needed",
+  "singleQuote": true,
+  "sortImports": {
+    "newlinesBetween": false,
+    "groups": [
+      ["builtin", "external"],
+      { "newlinesBetween": true },
+      ["internal", "parent", "sibling", "index", "unknown"]
+    ]
+  },
+  "tabWidth": 2,
+  "trailingComma": "all",
+  "ignorePatterns": [
+    "**/*-method-action-types.ts",
+    ".yarnrc.yml",
+    "merged-packages/**",
+    "CHANGELOG.md"
+  ]
+}

.oxfmtrc.json

@@ -1,6 +1,9 @@
-// All of these are defaults except singleQuote, but we specify them
-// for explicitness
+/**
+ * @type {import('prettier').Options}
+ */
 module.exports = {
+  // All of these are defaults except singleQuote, but we specify them
+  // for explicitness
   quoteProps: 'as-needed',
   singleQuote: true,
   tabWidth: 2,

.prettierrc.js

@@ -1,3 +1,3 @@
 {
-  "cSpell.words": ["bech32", "p2wpkh", "syncpack"]
+  "cSpell.words": ["bech32", "p2wpkh"]
 }

.syncpackrc

@@ -165,7 +165,6 @@ yarn dedupe
 
 - Use workspace protocol for internal dependencies: `"@metamask/keyring-api": "workspace:^"`
 - Run `yarn lint:dependencies:fix` after adding/updating packages
-- Check `syncpack` for version consistency across packages
 
 ---
 
@@ -453,11 +452,13 @@ enum AccountType {
 }
 
 // ❌ WRONG: Plural enum names
-enum EthMethods { // Don't use plural
+enum EthMethods {
+  // Don't use plural
   SignTransaction = 'eth_signTransaction',
 }
 
-enum AccountTypes { // Don't use plural
+enum AccountTypes {
+  // Don't use plural
   Eoa = 'eoa',
 }