Add Rails backend: accounts via magic link, server documents, sharing

The app becomes a Rails 8 application; the Vue frontend moves to
app/frontend and is served through vite_rails.

- Without an account documents stay in the browser (IndexedDB). Sign-in
  is by magic link or the 6-digit code from the same mail; afterwards
  local documents can be uploaded into the account.
- Server documents (/d/<id>) with versioned saves and a single-editor
  lock per browser tab; others see them read-only and follow by polling.
- Sharing via link (works without an account) and via e-mail invitation,
  roles viewer/editor; the owner manages links and people.
- Store gains a read-only mode that blocks all content changes.
- Solid Queue, Cache and Cable share the one PostgreSQL database.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

bin/brakeman

@@ -0,0 +1,7 @@
+#!/usr/bin/env ruby
+require "rubygems"
+require "bundler/setup"
+
+ARGV.unshift("--ensure-latest")
+
+load Gem.bin_path("brakeman", "brakeman")

bin/bundler-audit

@@ -0,0 +1,6 @@
+#!/usr/bin/env ruby
+require_relative "../config/boot"
+require "bundler/audit/cli"
+
+ARGV.concat %w[ --config config/bundler-audit.yml ] if ARGV.empty? || ARGV.include?("check")
+Bundler::Audit::CLI.start

bin/ci

@@ -0,0 +1,6 @@
+#!/usr/bin/env ruby
+require_relative "../config/boot"
+require "active_support/continuous_integration"
+
+CI = ActiveSupport::ContinuousIntegration
+require_relative "../config/ci.rb"

bin/dev

@@ -0,0 +1,9 @@
+#!/usr/bin/env sh
+# Rails (port 3000) + Vite dev server with HMR (port 3036), see Procfile.dev
+
+if ! gem list foreman -i --silent; then
+  echo "Installing foreman..."
+  gem install foreman
+fi
+
+exec foreman start -f Procfile.dev "$@"

bin/jobs

@@ -0,0 +1,6 @@
+#!/usr/bin/env ruby
+
+require_relative "../config/environment"
+require "solid_queue/cli"
+
+SolidQueue::Cli.start(ARGV)

bin/rails

@@ -0,0 +1,4 @@
+#!/usr/bin/env ruby
+APP_PATH = File.expand_path("../config/application", __dir__)
+require_relative "../config/boot"
+require "rails/commands"

bin/rake

@@ -0,0 +1,4 @@
+#!/usr/bin/env ruby
+require_relative "../config/boot"
+require "rake"
+Rake.application.run

bin/setup

@@ -0,0 +1,36 @@
+#!/usr/bin/env ruby
+require "fileutils"
+
+APP_ROOT = File.expand_path("..", __dir__)
+
+def system!(*args)
+  system(*args, exception: true)
+end
+
+FileUtils.chdir APP_ROOT do
+  # This script is a way to set up or update your development environment automatically.
+  # This script is idempotent, so that you can run it at any time and get an expectable outcome.
+  # Add necessary setup steps to this file.
+
+  puts "== Installing dependencies =="
+  system("bundle check") || system!("bundle install")
+  system! "npm install"
+
+  # puts "\n== Copying sample files =="
+  # unless File.exist?("config/database.yml")
+  #   FileUtils.cp "config/database.yml.sample", "config/database.yml"
+  # end
+
+  puts "\n== Preparing database =="
+  system! "bin/rails db:prepare"
+  system! "bin/rails db:reset" if ARGV.include?("--reset")
+
+  puts "\n== Removing old logs and tempfiles =="
+  system! "bin/rails log:clear tmp:clear"
+
+  unless ARGV.include?("--skip-server")
+    puts "\n== Starting development server =="
+    STDOUT.flush # flush the output before exec(2) so that it displays
+    exec "bin/dev"
+  end
+end

bin/vite

@@ -0,0 +1,27 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+#
+# This file was generated by Bundler.
+#
+# The application 'vite' is installed as part of a gem, and
+# this file is here to facilitate running it.
+#
+
+ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../Gemfile", __dir__)
+
+bundle_binstub = File.expand_path("bundle", __dir__)
+
+if File.file?(bundle_binstub)
+  if File.read(bundle_binstub, 300).include?("This file was generated by Bundler")
+    load(bundle_binstub)
+  else
+    abort("Your `bin/bundle` was not generated by Bundler, so this binstub cannot run.
+Replace `bin/bundle` by running `bundle binstubs bundler --force`, then run this command again.")
+  end
+end
+
+require "rubygems"
+require "bundler/setup"
+
+load Gem.bin_path("vite_ruby", "vite")