Add React on Rails Quick Start example application

This commit adds a complete example Rails application that demonstrates
the React on Rails setup process following our 15-minute quick-start guide.

## What's included:

### Complete Working Example
- Full Rails 7 + React 19 + Shakapacker 8.3 setup
- HelloWorld React component with interactive features
- Props passing from Rails controller to React component
- Hot Module Replacement (HMR) ready for development
- Server-side rendering capability (configurable)

### Generated Structure
- Rails controller, views, and routes
- React components with CSS modules
- Webpack configuration for client and server bundles
- Development scripts (bin/dev, bin/dev-static)
- Comprehensive README with usage instructions

### Validation of Documentation
- Proves the quick-start guide works exactly as documented
- Demonstrates expected file structure after setup
- Provides working reference for development and testing
- Shows best practices for React on Rails integration

## Purpose:
1. **Documentation validation** - Ensures our quick-start guide is accurate
2. **Developer reference** - Shows complete working example
3. **Testing resource** - Provides baseline for development and CI
4. **Onboarding aid** - Helps new users understand the setup

## Quick test:
```bash
cd spec/quick-start
bundle install && npm install
./bin/dev
# Visit http://localhost:3000/hello_world
```

This example serves as both documentation validation and a practical
reference for developers getting started with React on Rails.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: justin808

spec/quick-start

@@ -0,0 +1,48 @@
+# See https://docs.docker.com/engine/reference/builder/#dockerignore-file for more about ignoring files.
+
+# Ignore git directory.
+/.git/
+/.gitignore
+
+# Ignore bundler config.
+/.bundle
+
+# Ignore all environment files (except templates).
+/.env*
+!/.env*.erb
+
+# Ignore all default key files.
+/config/master.key
+/config/credentials/*.key
+
+# Ignore all logfiles and tempfiles.
+/log/*
+/tmp/*
+!/log/.keep
+!/tmp/.keep
+
+# Ignore pidfiles, but keep the directory.
+/tmp/pids/*
+!/tmp/pids/.keep
+
+# Ignore storage (uploaded files in development and any SQLite databases).
+/storage/*
+!/storage/.keep
+/tmp/storage/*
+!/tmp/storage/.keep
+
+# Ignore assets.
+/node_modules/
+/app/assets/builds/*
+!/app/assets/builds/.keep
+/public/assets
+
+# Ignore CI service files.
+/.github
+
+# Ignore development files
+/.devcontainer
+
+# Ignore Docker-related files
+/.dockerignore
+/Dockerfile*

spec/quick-start/.dockerignore

@@ -0,0 +1,12 @@
+version: 2
+updates:
+- package-ecosystem: bundler
+  directory: "/"
+  schedule:
+    interval: daily
+  open-pull-requests-limit: 10
+- package-ecosystem: github-actions
+  directory: "/"
+  schedule:
+    interval: daily
+  open-pull-requests-limit: 10

spec/quick-start/.github/dependabot.yml

@@ -0,0 +1,90 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches: [ main ]
+
+jobs:
+  scan_ruby:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: .ruby-version
+          bundler-cache: true
+
+      - name: Scan for common Rails security vulnerabilities using static analysis
+        run: bin/brakeman --no-pager
+
+  scan_js:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: .ruby-version
+          bundler-cache: true
+
+      - name: Scan for security vulnerabilities in JavaScript dependencies
+        run: bin/importmap audit
+
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: .ruby-version
+          bundler-cache: true
+
+      - name: Lint code for consistent style
+        run: bin/rubocop -f github
+
+  test:
+    runs-on: ubuntu-latest
+
+    # services:
+    #  redis:
+    #    image: redis
+    #    ports:
+    #      - 6379:6379
+    #    options: --health-cmd "redis-cli ping" --health-interval 10s --health-timeout 5s --health-retries 5
+    steps:
+      - name: Install packages
+        run: sudo apt-get update && sudo apt-get install --no-install-recommends -y google-chrome-stable curl libjemalloc2 libvips sqlite3
+
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: .ruby-version
+          bundler-cache: true
+
+      - name: Run tests
+        env:
+          RAILS_ENV: test
+          # REDIS_URL: redis://localhost:6379/0
+        run: bin/rails db:test:prepare test test:system
+
+      - name: Keep screenshots from failed system tests
+        uses: actions/upload-artifact@v4
+        if: failure()
+        with:
+          name: screenshots
+          path: ${{ github.workspace }}/tmp/screenshots
+          if-no-files-found: ignore

spec/quick-start/.github/workflows/ci.yml

@@ -0,0 +1,8 @@
+# Omakase Ruby styling for Rails
+inherit_gem: { rubocop-rails-omakase: rubocop.yml }
+
+# Overwrite or add rules to create your own house style
+#
+# # Use `[a, [b, c]]` not `[ a, [ b, c ] ]`
+# Layout/SpaceInsideArrayLiteralBrackets:
+#   Enabled: false

spec/quick-start/.rubocop.yml

@@ -0,0 +1,69 @@
+# syntax = docker/dockerfile:1
+
+# This Dockerfile is designed for production, not development. Use with Kamal or build'n'run by hand:
+# docker build -t my-app .
+# docker run -d -p 80:80 -p 443:443 --name my-app -e RAILS_MASTER_KEY=<value from config/master.key> my-app
+
+# Make sure RUBY_VERSION matches the Ruby version in .ruby-version
+ARG RUBY_VERSION=3.3.7
+FROM docker.io/library/ruby:$RUBY_VERSION-slim AS base
+
+# Rails app lives here
+WORKDIR /rails
+
+# Install base packages
+RUN apt-get update -qq && \
+    apt-get install --no-install-recommends -y curl libjemalloc2 libvips sqlite3 && \
+    rm -rf /var/lib/apt/lists /var/cache/apt/archives
+
+# Set production environment
+ENV RAILS_ENV="production" \
+    BUNDLE_DEPLOYMENT="1" \
+    BUNDLE_PATH="/usr/local/bundle" \
+    BUNDLE_WITHOUT="development"
+
+# Throw-away build stage to reduce size of final image
+FROM base AS build
+
+# Install packages needed to build gems
+RUN apt-get update -qq && \
+    apt-get install --no-install-recommends -y build-essential git pkg-config && \
+    rm -rf /var/lib/apt/lists /var/cache/apt/archives
+
+# Install application gems
+COPY Gemfile Gemfile.lock ./
+RUN bundle install && \
+    rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
+    bundle exec bootsnap precompile --gemfile
+
+# Copy application code
+COPY . .
+
+# Precompile bootsnap code for faster boot times
+RUN bundle exec bootsnap precompile app/ lib/
+
+# Precompiling assets for production without requiring secret RAILS_MASTER_KEY
+RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
+
+
+
+
+# Final stage for app image
+FROM base
+
+# Copy built artifacts: gems, application
+COPY --from=build "${BUNDLE_PATH}" "${BUNDLE_PATH}"
+COPY --from=build /rails /rails
+
+# Run and own only the runtime files as a non-root user for security
+RUN groupadd --system --gid 1000 rails && \
+    useradd rails --uid 1000 --gid 1000 --create-home --shell /bin/bash && \
+    chown -R rails:rails db log storage tmp
+USER 1000:1000
+
+# Entrypoint prepares the database.
+ENTRYPOINT ["/rails/bin/docker-entrypoint"]
+
+# Start the server by default, this can be overwritten at runtime
+EXPOSE 3000
+CMD ["./bin/rails", "server"]

spec/quick-start/Dockerfile

@@ -0,0 +1,54 @@
+source "https://rubygems.org"
+
+# Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main"
+gem "rails", "~> 7.2.2", ">= 7.2.2.1"
+# The original asset pipeline for Rails [https://github.com/rails/sprockets-rails]
+gem "sprockets-rails"
+# Use sqlite3 as the database for Active Record
+gem "sqlite3", ">= 1.4"
+# Use the Puma web server [https://github.com/puma/puma]
+gem "puma", ">= 5.0"
+# Build JSON APIs with ease [https://github.com/rails/jbuilder]
+gem "jbuilder"
+# Use Redis adapter to run Action Cable in production
+# gem "redis", ">= 4.0.1"
+
+# Use Kredis to get higher-level data types in Redis [https://github.com/rails/kredis]
+# gem "kredis"
+
+# Use Active Model has_secure_password [https://guides.rubyonrails.org/active_model_basics.html#securepassword]
+# gem "bcrypt", "~> 3.1.7"
+
+# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
+gem "tzinfo-data", platforms: %i[ windows jruby ]
+
+# Reduces boot times through caching; required in config/boot.rb
+gem "bootsnap", require: false
+
+# Use Active Storage variants [https://guides.rubyonrails.org/active_storage_overview.html#transforming-images]
+# gem "image_processing", "~> 1.2"
+
+group :development, :test do
+  # See https://guides.rubyonrails.org/debugging_rails_applications.html#debugging-with-the-debug-gem
+  gem "debug", platforms: %i[ mri windows ], require: "debug/prelude"
+
+  # Static analysis for security vulnerabilities [https://brakemanscanner.org/]
+  gem "brakeman", require: false
+
+  # Omakase Ruby styling [https://github.com/rails/rubocop-rails-omakase/]
+  gem "rubocop-rails-omakase", require: false
+end
+
+group :development do
+  # Use console on exceptions pages [https://github.com/rails/web-console]
+  gem "web-console"
+end
+
+group :test do
+  # Use system testing [https://guides.rubyonrails.org/testing.html#system-testing]
+  gem "capybara"
+  gem "selenium-webdriver"
+end
+
+gem "shakapacker", "= 8.3"
+gem "react_on_rails", path: "../.."