Feature: Upgrade Ruby to version 4.0.0

.ruby-version

@@ -1 +1 @@
-3.4.4
+4.0.0

CLAUDE.md

@@ -0,0 +1,242 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+WhyRuby.info is a Ruby advocacy community website built with Rails 8.1 (edge/main branch) and the Solid Stack (SQLite, SolidQueue, SolidCache, SolidCable). It features a universal content model supporting articles, links, and success stories with AI-generated summaries, GitHub OAuth authentication, and community-driven content moderation.
+
+## Development Commands
+
+### Server Management
+```bash
+# Start the development server (REQUIRED - do not use rails server directly)
+bin/dev
+
+# Monitor logs in real-time
+tail -f log/development.log
+```
+
+**IMPORTANT**: Always use `bin/dev` instead of `rails server`. This starts both the Rails server (port 3003) and Tailwind CSS watcher via Procfile.dev.
+
+### Database
+```bash
+# Create and setup database
+rails db:create
+rails db:migrate
+rails db:seed
+
+# Database console
+rails db
+
+# Promote user to admin
+rails runner "User.find_by(username: 'github-username').update!(role: :admin)"
+```
+
+### Testing & Code Quality
+```bash
+# Run all tests
+rails test
+
+# Run single test file
+rails test test/models/post_test.rb
+
+# Run single test
+rails test test/models/post_test.rb:line_number
+
+# Code style (auto-fixes and stages changes via lefthook)
+bundle exec rubocop
+bundle exec rubocop -A  # Auto-correct issues
+```
+
+### Rails Console & Generators
+```bash
+# Console
+rails console
+
+# Generate model with ULID primary key
+rails generate model ModelName
+
+# Other generators
+rails generate controller ControllerName
+rails generate migration MigrationName
+```
+
+## Architecture & Key Patterns
+
+### Data Model Structure
+
+The application uses a **Universal Content Model** where the `Post` model handles three distinct content types via the `post_type` enum:
+
+- **Articles**: Original content with markdown (`content` field required, `url` must be blank)
+- **Links**: External content (`url` required, `content` must be blank)
+- **Success Stories**: Ruby success stories with SVG logo (`logo_svg` and `content` required, `url` must be blank)
+
+**Key Models:**
+- `User`: GitHub OAuth authentication, role-based access (member/admin), trusted user system based on contribution counts (3+ published posts, 10+ published comments)
+- `Post`: Universal content model with FriendlyId slugs, soft deletion via `archived` flag, counter caches for reports
+- `Category`: Content organization with position ordering, special success story category flag
+- `Tag`: HABTM relationship with posts
+- `Comment`: User feedback on posts with published flag
+- `Report`: Content moderation by trusted users, auto-hides after 3+ reports
+
+### Primary Keys & IDs
+
+**All tables use ULID instead of integer IDs:**
+```ruby
+create_table :table_name, force: true, id: false do |t|
+  t.primary_key :id, :string, default: -> { "ULID()" }
+  # ...
+end
+```
+
+This is configured via the `sqlite-ulid` gem and provides better distribution and sortability.
+
+### Authentication & Authorization
+
+- **Authentication**: GitHub OAuth only via Devise + OmniAuth
+- **Roles**: `member` (default) and `admin` (enum in User model)
+- **Trusted Users**: Automatically qualified when `published_posts_count >= 3` AND `published_comments_count >= 10`
+- **Permissions**: Only trusted users can report content; only admins can access `/admin` (Avo panel)
+
+### Content Moderation Flow
+
+1. Trusted users can report inappropriate content
+2. After 3+ reports, content is automatically:
+   - Set to `published: false`
+   - Flagged with `needs_admin_review: true`
+   - Admin notification sent via `NotifyAdminJob`
+3. Admins review and restore or permanently archive via Avo panel
+
+### Background Jobs (SolidQueue)
+
+- `GenerateSummaryJob`: Creates AI summaries for new/updated posts using OpenAI or Anthropic APIs
+- `GenerateSuccessStoryImageJob`: Generates OG images for success stories from SVG logos
+- `NotifyAdminJob`: Sends notifications when content is auto-hidden
+- `UpdateGithubDataJob`: Refreshes user GitHub data (repositories, stars, etc.)
+
+### Image Processing
+
+Posts support `featured_image` attachments via ActiveStorage. Images are processed into multiple variants (small, medium, large, og) and stored as separate blobs with metadata in `image_variants` JSON column. Processing uses the `ImageProcessor` service.
+
+### URL Routing Pattern
+
+The application uses a **catch-all routing strategy** for clean URLs:
+
+```
+/:category_slug              # Category pages
+/:category_slug/:post_slug   # Post pages
+```
+
+**Important**: Category and post routes use constraints and are defined at the END of routes.rb to avoid conflicts with explicit routes like `/admin`, `/community`, `/legal/*`, etc.
+
+### Services Layer
+
+Service objects in `app/services/` handle complex operations:
+- `GithubDataFetcher`: Fetches and updates user GitHub profile data and repositories on sign-in
+- `ImageProcessor`: Processes featured images into multiple variants (small, medium, large, og)
+- `SuccessStoryImageGenerator`: Generates OG images for success stories from SVG logos
+- `SvgSanitizer`: Sanitizes SVG content to prevent XSS attacks
+
+### FriendlyId Implementation
+
+Both `User` and `Post` models use FriendlyId with history:
+- `User`: Slugs from `username`
+- `Post`: Slugs from `title`
+
+Both models implement `create_slug_history` to manually save old slugs when changed, ensuring historical URLs redirect properly.
+
+## Rails 8 Specific Patterns
+
+### Solid Stack Usage
+
+- **SolidQueue**: Default background job processor (no Redis needed)
+- **SolidCache**: Database-backed caching
+- **SolidCable**: WebSocket functionality via SQLite
+- Configuration files: `config/queue.yml`, `config/cache.yml`, `config/cable.yml`
+
+### Modern Rails 8 Conventions
+
+- Use `params.expect()` for parameter handling instead of strong parameters (Rails 8.1 feature)
+- Propshaft for asset pipeline (not Sprockets)
+- Tailwind CSS 4 via `tailwindcss-rails` gem
+- Hotwire (Turbo + Stimulus) for frontend interactivity
+
+### Migrations
+
+Always use ULID primary keys. Never use auto-increment integers:
+
+```ruby
+create_table :posts, force: true, id: false do |t|
+  t.primary_key :id, :string, default: -> { "ULID()" }
+  t.string :title, null: false
+  # ...
+end
+```
+
+## Important Development Practices
+
+### Server & Logging
+
+- **ALWAYS** use `bin/dev` to start the server
+- Check logs after every significant change
+- Monitor `log/development.log` for errors and performance issues
+- Review logs before considering any change complete
+
+### Code Style
+
+The project uses lefthook to automatically run RuboCop before commits:
+- RuboCop runs with auto-fix (`-A`) on all files
+- Fixed files are automatically staged
+- Configuration in `.lefthook.yml` and `.rubocop.yml`
+
+### Testing
+
+- Framework: Minitest (Rails default)
+- Fixtures in `test/fixtures/`
+- Test structure: `test/models/`, `test/controllers/`, `test/system/`
+- Run tests before committing
+
+## Credentials & Configuration
+
+### Development Credentials
+
+```bash
+rails credentials:edit --environment development
+```
+
+Required credentials:
+```yaml
+github:
+  client_id: your_github_oauth_app_client_id
+  client_secret: your_github_oauth_app_client_secret
+
+openai:
+  api_key: your_openai_api_key  # Optional - for AI summaries
+```
+
+### GitHub OAuth Setup
+
+1. Create OAuth App at: https://github.com/settings/developers
+2. Set callback URL: `http://localhost:3000/users/auth/github/callback`
+3. Add credentials to development credentials file
+
+### Deployment
+
+- Configured for Kamal 2 deployment (see `config/deploy.yml`)
+- Litestream for SQLite backups to S3 (see `config/litestream.yml`)
+- RorVsWild for performance monitoring (see `config/rorvswild.yml`)
+
+## Admin Panel
+
+- Admin panel powered by Avo (v3.2+)
+- Route: `/admin` (only accessible to admin users)
+- Configuration: `app/avo/` directory
+- Litestream backup UI: `/litestream` (admin only)
+
+## Markdown Rendering
+
+- Redcarpet for markdown parsing
+- Rouge for syntax highlighting
+- Markdown content stored in `Post#content` field for articles and success stories
+- Custom helper: `ApplicationHelper#render_markdown_with_syntax_highlighting`

Dockerfile

@@ -8,7 +8,7 @@
 # For a containerized dev environment, see Dev Containers: https://guides.rubyonrails.org/getting_started_with_devcontainer.html
 
 # Make sure RUBY_VERSION matches the Ruby version in .ruby-version
-ARG RUBY_VERSION=3.4.4
+ARG RUBY_VERSION=4.0.0
 FROM docker.io/library/ruby:$RUBY_VERSION-slim AS base
 
 # Rails app lives here

Gemfile

@@ -37,9 +37,6 @@ gem "kamal", require: false
 # Add HTTP asset caching/compression and X-Sendfile acceleration to Puma [https://github.com/basecamp/thruster/]
 gem "thruster", require: false
 
-# Fetch metadata from URLs
-gem "metainspector"
-
 # Authentication
 gem "devise", "~> 4.9"
 gem "omniauth-github", "~> 2.0"