feat: add new ConnectivityController (#7623)

## Explanation

This PR introduces a new `@metamask/connectivity-controller` package
that provides a centralized way to track and manage device internet
connectivity status across MetaMask clients (extension and mobile).

**What is the current state of things and why does it need to change?**

- Have a single source of truth for connectivity state
- Share connectivity status across controllers and UI components
- Test connectivity-related functionality in isolation
- Maintain consistent behavior across platforms

**What is the solution your changes offer and how does it work?**

The `ConnectivityController` is a platform-agnostic controller that:
- Stores the current connectivity status (`online` or `offline`) in its
state
- Uses a service injection pattern where platform-specific
`ConnectivityService` implementations are injected at construction time
- Subscribes to connectivity changes from the service and automatically
updates its state
- Emits `stateChange` events when connectivity status changes, allowing
other controllers and UI components to react accordingly

The controller is designed to work with different service
implementations:
- **Mobile**: `NetInfoConnectivityService` using
`@react-native-community/netinfo`
- **Extension (same context)**: `BrowserConnectivityService` using
browser APIs

**Are there any changes whose purpose might not be obvious to those
unfamiliar with the domain?**

- The `connectivityStatus` field in state is prefixed with
"connectivity" to avoid conflicts when state is flattened in Redux
- The state is configured with `persist: false` since connectivity
status is ephemeral and should not be restored from storage

## References

Fixes: https://consensyssoftware.atlassian.net/browse/WPC-210


<!--
Add any relevant issues, related PRs, or documentation links here
-->

## 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](https://github.com/MetaMask/core/tree/main/docs/processes/updating-changelogs.md)
- [ ] I've introduced [breaking
changes](https://github.com/MetaMask/core/tree/main/docs/processes/breaking-changes.md)
in this PR and have prepared draft pull requests for clients and
consumer packages to resolve them


<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> Introduce a new, platform-agnostic controller to track device
connectivity with adapter-driven status updates.
> 
> - New package `@metamask/connectivity-controller` exposing
`ConnectivityController`, `CONNECTIVITY_STATUSES`, and
`ConnectivityAdapter` interface
> - Controller initializes from adapter `getStatus()` and updates state
on `onConnectivityChange`, with non-persistent `connectivityStatus`
metadata
> - Comprehensive tests for initialization and status change handling;
100% coverage config
> - Added package docs (README, CHANGELOG, LICENSE) and build/test
configs (tsconfig, typedoc, jest)
> - Monorepo integration: README package list/graph, `CODEOWNERS`,
`teams.json`, tsconfig references, and `yarn.lock` entry
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
16c51b5. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: cryptodev-2s

.github/CODEOWNERS

@@ -68,6 +68,7 @@
 /packages/base-controller              @MetaMask/core-platform
 /packages/build-utils                  @MetaMask/core-platform
 /packages/composable-controller        @MetaMask/core-platform
+/packages/connectivity-controller      @MetaMask/core-platform
 /packages/controller-utils             @MetaMask/core-platform
 /packages/error-reporting-service      @MetaMask/core-platform
 /packages/eth-json-rpc-middleware      @MetaMask/core-platform

README.md

@@ -36,6 +36,7 @@ Each package in this repository has its own README where you can find installati
 - [`@metamask/chain-agnostic-permission`](packages/chain-agnostic-permission)
 - [`@metamask/claims-controller`](packages/claims-controller)
 - [`@metamask/composable-controller`](packages/composable-controller)
+- [`@metamask/connectivity-controller`](packages/connectivity-controller)
 - [`@metamask/controller-utils`](packages/controller-utils)
 - [`@metamask/core-backend`](packages/core-backend)
 - [`@metamask/delegation-controller`](packages/delegation-controller)
@@ -111,6 +112,7 @@ linkStyle default opacity:0.5
   chain_agnostic_permission(["@metamask/chain-agnostic-permission"]);
   claims_controller(["@metamask/claims-controller"]);
   composable_controller(["@metamask/composable-controller"]);
+  connectivity_controller(["@metamask/connectivity-controller"]);
   controller_utils(["@metamask/controller-utils"]);
   core_backend(["@metamask/core-backend"]);
   delegation_controller(["@metamask/delegation-controller"]);
@@ -231,6 +233,8 @@ linkStyle default opacity:0.5
   composable_controller --> base_controller;
   composable_controller --> messenger;
   composable_controller --> json_rpc_engine;
+  connectivity_controller --> base_controller;
+  connectivity_controller --> messenger;
   core_backend --> accounts_controller;
   core_backend --> controller_utils;
   core_backend --> keyring_controller;

packages/connectivity-controller/CHANGELOG.md

@@ -0,0 +1,14 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+### Added
+
+- Initial release ([#7623](https://github.com/MetaMask/core/pull/7623))
+
+[Unreleased]: https://github.com/MetaMask/core/

packages/connectivity-controller/LICENSE

@@ -0,0 +1,20 @@
+MIT License
+
+Copyright (c) 2026 MetaMask
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

packages/connectivity-controller/README.md

@@ -0,0 +1,15 @@
+# `@metamask/connectivity-controller`
+
+ConnectivityController stores the device's internet connectivity status.
+
+## Installation
+
+`yarn add @metamask/connectivity-controller`
+
+or
+
+`npm install @metamask/connectivity-controller`
+
+## Contributing
+
+This package is part of a monorepo. Instructions for contributing can be found in the [monorepo README](https://github.com/MetaMask/core#readme).

packages/connectivity-controller/jest.config.js

@@ -0,0 +1,26 @@
+/*
+ * For a detailed explanation regarding each configuration property and type check, visit:
+ * https://jestjs.io/docs/configuration
+ */
+
+const merge = require('deepmerge');
+const path = require('path');
+
+const baseConfig = require('../../jest.config.packages');
+
+const displayName = path.basename(__dirname);
+
+module.exports = merge(baseConfig, {
+  // The display name when running multiple projects
+  displayName,
+
+  // An object that configures minimum threshold enforcement for coverage results
+  coverageThreshold: {
+    global: {
+      branches: 100,
+      functions: 100,
+      lines: 100,
+      statements: 100,
+    },
+  },
+});

packages/connectivity-controller/package.json

@@ -0,0 +1,72 @@
+{
+  "name": "@metamask/connectivity-controller",
+  "version": "0.0.0",
+  "description": "ConnectivityController stores the device's internet connectivity status",
+  "keywords": [
+    "MetaMask",
+    "Ethereum"
+  ],
+  "homepage": "https://github.com/MetaMask/core/tree/main/packages/connectivity-controller#readme",
+  "bugs": {
+    "url": "https://github.com/MetaMask/core/issues"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/MetaMask/core.git"
+  },
+  "license": "MIT",
+  "sideEffects": false,
+  "exports": {
+    ".": {
+      "import": {
+        "types": "./dist/index.d.mts",
+        "default": "./dist/index.mjs"
+      },
+      "require": {
+        "types": "./dist/index.d.cts",
+        "default": "./dist/index.cjs"
+      }
+    },
+    "./package.json": "./package.json"
+  },
+  "main": "./dist/index.cjs",
+  "types": "./dist/index.d.cts",
+  "files": [
+    "dist/"
+  ],
+  "scripts": {
+    "build": "ts-bridge --project tsconfig.build.json --verbose --clean --no-references",
+    "build:all": "ts-bridge --project tsconfig.build.json --verbose --clean",
+    "build:docs": "typedoc",
+    "changelog:update": "../../scripts/update-changelog.sh @metamask/connectivity-controller",
+    "changelog:validate": "../../scripts/validate-changelog.sh @metamask/connectivity-controller",
+    "publish:preview": "yarn npm publish --tag preview",
+    "since-latest-release": "../../scripts/since-latest-release.sh",
+    "test": "NODE_OPTIONS=--experimental-vm-modules jest --reporters=jest-silent-reporter",
+    "test:clean": "NODE_OPTIONS=--experimental-vm-modules jest --clearCache",
+    "test:verbose": "NODE_OPTIONS=--experimental-vm-modules jest --verbose",
+    "test:watch": "NODE_OPTIONS=--experimental-vm-modules jest --watch"
+  },
+  "dependencies": {
+    "@metamask/base-controller": "^9.0.0",
+    "@metamask/messenger": "^0.3.0"
+  },
+  "devDependencies": {
+    "@metamask/auto-changelog": "^3.4.4",
+    "@ts-bridge/cli": "^0.6.4",
+    "@types/jest": "^27.4.1",
+    "deepmerge": "^4.2.2",
+    "jest": "^27.5.1",
+    "ts-jest": "^27.1.4",
+    "typedoc": "^0.24.8",
+    "typedoc-plugin-missing-exports": "^2.0.0",
+    "typescript": "~5.3.3"
+  },
+  "engines": {
+    "node": "^18.18 || >=20"
+  },
+  "publishConfig": {
+    "access": "public",
+    "registry": "https://registry.npmjs.org/"
+  }
+}