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>

config/environments/production.rb

@@ -0,0 +1,88 @@
+require "active_support/core_ext/integer/time"
+
+Rails.application.configure do
+  # Settings specified here will take precedence over those in config/application.rb.
+
+  # Code is not reloaded between requests.
+  config.enable_reloading = false
+
+  # Eager load code on boot for better performance and memory savings (ignored by Rake tasks).
+  config.eager_load = true
+
+  # Full error reports are disabled.
+  config.consider_all_requests_local = false
+
+  # Turn on fragment caching in view templates.
+  config.action_controller.perform_caching = true
+
+  # Cache assets for far-future expiry since they are all digest stamped.
+  config.public_file_server.headers = { "cache-control" => "public, max-age=#{1.year.to_i}" }
+
+  # Enable serving of images, stylesheets, and JavaScripts from an asset server.
+  # config.asset_host = "http://assets.example.com"
+
+  # Assume all access to the app is happening through a SSL-terminating reverse proxy.
+  config.assume_ssl = true
+
+  # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
+  config.force_ssl = true
+
+  # Skip http-to-https redirect for the default health check endpoint.
+  # config.ssl_options = { redirect: { exclude: ->(request) { request.path == "/up" } } }
+
+  # Log to STDOUT with the current request id as a default log tag.
+  config.log_tags = [ :request_id ]
+  config.logger   = ActiveSupport::TaggedLogging.logger(STDOUT)
+
+  # Change to "debug" to log everything (including potentially personally-identifiable information!).
+  config.log_level = ENV.fetch("RAILS_LOG_LEVEL", "info")
+
+  # Prevent health checks from clogging up the logs.
+  config.silence_healthcheck_path = "/up"
+
+  # Don't log any deprecations.
+  config.active_support.report_deprecations = false
+
+  # Replace the default in-process memory cache store with a durable alternative.
+  config.cache_store = :solid_cache_store
+
+  # Replace the default in-process and non-durable queuing backend for Active Job.
+  config.active_job.queue_adapter = :solid_queue
+
+  # Ignore bad email addresses and do not raise email delivery errors.
+  # Set this to true and configure the email server for immediate delivery to raise delivery errors.
+  # config.action_mailer.raise_delivery_errors = false
+
+  # Set host to be used by links generated in mailer templates.
+  config.action_mailer.default_url_options = { host: ENV.fetch("NUMOLUS_HOST", "numolus.wicom.li"), protocol: "https" }
+
+  # Outgoing SMTP server, configured by environment variables.
+  config.action_mailer.delivery_method = :smtp
+  config.action_mailer.smtp_settings = {
+    address: ENV["SMTP_ADDRESS"],
+    port: ENV.fetch("SMTP_PORT", 587).to_i,
+    user_name: ENV["SMTP_USER_NAME"],
+    password: ENV["SMTP_PASSWORD"],
+    authentication: :plain,
+    enable_starttls_auto: true
+  }
+
+  # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
+  # the I18n.default_locale when a translation cannot be found).
+  config.i18n.fallbacks = true
+
+  # Do not dump schema after migrations.
+  config.active_record.dump_schema_after_migration = false
+
+  # Only use :id for inspections in production.
+  config.active_record.attributes_for_inspect = [ :id ]
+
+  # Enable DNS rebinding protection and other `Host` header attacks.
+  # config.hosts = [
+  #   "example.com",     # Allow requests from example.com
+  #   /.*\.example\.com/ # Allow requests from subdomains like `www.example.com`
+  # ]
+  #
+  # Skip DNS rebinding protection for the default health check endpoint.
+  # config.host_authorization = { exclude: ->(request) { request.path == "/up" } }
+end