Release v0.1.0

🚀 Changes:

• Isolated Rails Engine mounted with mount Waitmate::Engine => "/waitmate".
• wait_room :action, max_concurrent: N controller concern for gating expensive actions.
• Encrypted admission tickets via ActiveSupport::MessageEncryptor, bound to queue, expiry, and session identity.
• Redis primary storage adapter with atomic Lua-based enqueue, admit, release, and position operations.
• Solid Cache SQL fallback adapter using SolidCache::Entry.
• HTTP-polling waiting-room page at /waitmate/room, with a /waitmate/room/position endpoint that doubles as a heartbeat.
• Configurable adapter, queue_ttl, polling_interval, ticket_ttl, and waiting_room_path.
• Host-app override of the waiting-room view via app/views/waitmate/rooms/show.html.erb.
• rails generate waitmate:install generator that copies config/initializers/waitmate.rb.
• RSpec test suite, StandardRB linting, and bundler-audit security gate run by bin/quality.

🛠️ Limitations:

• HTTP polling only; ActionCable/Turbo Streams are not implemented.
• Controller-concern integration only; no Rack middleware.
• Redis and Solid Cache are the only supported storage adapters.
• Rails-only; no standalone Rack or non-Rails support.
• Single waiting-room page; no admin dashboard, CAPTCHA, or anti-bot functionality.