refactor: modernize project tooling and simplify architecture

Replace CircleCI with GitHub Actions, remove old/new arch split in favor of
unified Android module, migrate example app to Expo, and add modern tooling
(ESLint flat config, lefthook, Turborepo, Yarn Berry).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: mrbrentkelly

.circleci/config.yml

@@ -1,3 +1,3 @@
 *.pbxproj -text
 # specific for windows script files
-*.bat text eol=crlf
+*.bat text eol=crlf

.gitattributes

@@ -0,0 +1,67 @@
+name: 🐛 Bug report
+description: Report a reproducible bug or regression in this library.
+labels: [bug]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        # Bug report
+
+        👋 Hi!
+
+        **Please fill the following carefully before opening a new issue ❗**
+        *(Your issue may be closed if it doesn't provide the required pieces of information)*
+  - type: checkboxes
+    attributes:
+      label: Before submitting a new issue
+      description: Please perform simple checks first.
+      options:
+        - label: I tested using the latest version of the library, as the bug might be already fixed.
+          required: true
+        - label: I tested using a [supported version](https://github.com/reactwg/react-native-releases/blob/main/docs/support.md) of react native.
+          required: true
+        - label: I checked for possible duplicate issues, with possible answers.
+          required: true
+  - type: textarea
+    id: summary
+    attributes:
+      label: Bug summary
+      description: |
+        Provide a clear and concise description of what the bug is.
+        If needed, you can also provide other samples: error messages / stack traces, screenshots, gifs, etc.
+    validations:
+      required: true
+  - type: input
+    id: library-version
+    attributes:
+      label: Library version
+      description: What version of the library are you using?
+      placeholder: "x.x.x"
+    validations:
+      required: true
+  - type: textarea
+    id: react-native-info
+    attributes:
+      label: Environment info
+      description: Run `react-native info` in your terminal and paste the results here.
+      render: shell
+    validations:
+      required: true
+  - type: textarea
+    id: steps-to-reproduce
+    attributes:
+      label: Steps to reproduce
+      description: |
+        You must provide a clear list of steps and code to reproduce the problem.
+      value: |
+        1. …
+        2. …
+    validations:
+      required: true
+  - type: input
+    id: reproducible-example
+    attributes:
+      label: Reproducible example repository 
+      description: Please provide a link to a repository on GitHub with a reproducible example.
+    validations:
+      required: true

.github/CODEOWNERS

@@ -0,0 +1,8 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Feature Request 💡
+    url: https://github.com/hudl/react-native-system-bars/discussions/new?category=ideas
+    about: If you have a feature request, please create a new discussion on GitHub.
+  - name: Discussions on GitHub 💬
+    url: https://github.com/hudl/react-native-system-bars/discussions
+    about: If this library works as promised but you need help, please ask questions there.

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,37 @@
+name: CI
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  ci:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 20
+
+      - name: Enable Corepack
+        run: corepack enable
+
+      - name: Install dependencies
+        run: yarn install --frozen-lockfile
+
+      - name: Lint
+        run: yarn lint --max-warnings 0
+
+      - name: Build
+        run: yarn prepare

.github/ISSUE_TEMPLATE/config.yml

@@ -6,6 +6,7 @@
 .expo/
 
 # VSCode
+.vscode/
 jsconfig.json
 
 # Xcode
@@ -26,21 +27,26 @@ DerivedData
 *.hmap
 *.ipa
 *.xcuserstate
-ios/.xcode.env.local
 project.xcworkspace
+**/.xcode.env.local
 
 # Android/IJ
 #
-.idea
+.classpath
+.cxx
 .gradle
+.idea
+.project
+.settings
 local.properties
 android.iml
-*.hprof
 
-# Ruby / Cocoapods
+# Cocoapods
 #
 example/ios/Pods
-/vendor/bundle/
+
+# Ruby
+example/vendor/
 
 # node.js
 #
@@ -55,13 +61,25 @@ buck-out/
 android/app/libs
 android/keystores/debug.keystore
 
+# Yarn
+.yarn/*
+!.yarn/patches
+!.yarn/plugins
+!.yarn/sdks
+!.yarn/versions
+
 # Expo
-.expo/*
+.expo/
+
+# Turborepo
+.turbo/
 
 # generated by bob
 lib/
 
-**/fastlane/report.xml
-**/fastlane/Preview.html
-**/fastlane/screenshots
-**/fastlane/test_output
+# React Native Codegen
+ios/generated
+android/generated
+
+# React Native Nitro Modules
+nitrogen/

.github/workflows/ci.yml

@@ -0,0 +1 @@
+v22.20.0