No application code reads ENV, and the wiki has one address again

The API read its environment wherever it happened to need it: `Image` in the
model, `RssService` and `WikiService` in class-level constants, the softwares
admin page in a sidebar. Two of those wanted the same wiki and disagreed about
its name — `RssService::WIKI_URL` against `WikiService::GRAV_URL` — and only
the second one is set in docker-compose, so the howtos feed had been linking to
the hard-coded default all along.

Every `ENV` read is in `config/application.rb` now, as `config.x.site_url`,
`config.x.wiki_url` and `config.x.images.container_path`, and the code asks
`Rails.configuration.x`. One place says what this app needs from its
environment, and a test can override it.

`RssService` was three copies of the same twenty-line `RSS::Maker` block. It is
`Rss::Feed` plus `Rss::BlogFeed`, `Rss::ReleasesFeed` and `Rss::HowtosFeed`,
each of which now only answers what its title, its link and its items are — and
the `Time.parse(...) rescue Time.current` modifier, which swallowed everything,
is a rescue of ArgumentError and TypeError. `WikiService` becomes `Wiki::Pages`
and loses `alias_method :pages, :index`: two names for one method meant the
controller and the feeds each called it something different.

The admin cookie was a monkey patch — `ApplicationController.class_eval` in an
initializer, adding an `after_action` that the three-line controller file gave
no hint of. It is a `SyncsAdminCookie` concern the controller includes.

And the engine stops reading the host's config keys: the "View on site" link in
the softwares admin asked for `Rails.configuration.x.site_url`, which is ours,
not its. `c.site_url` is an engine setting now, nil by default, and the link is
left out when the host does not set it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

apps/api/config/application.rb

@@ -25,5 +25,9 @@ module Api
     config.action_controller.forgery_protection_origin_check = false
 
     config.autoload_lib(ignore: %w[assets tasks])
+
+    config.x.site_url             = ENV.fetch("SITE_URL", "https://teletypegames.org")
+    config.x.wiki_url             = ENV.fetch("WIKI_GRAV_URL", "https://wiki.teletypegames.org")
+    config.x.images.container_path = ENV.fetch("IMAGE_CONTAINER_PATH", "/images")
   end
 end

apps/api/config/initializers/admin_cookie.rb

@@ -1,15 +0,0 @@
-Rails.application.config.to_prepare do
-  ApplicationController.class_eval do
-    after_action :sync_admin_cookie
-
-    private
-
-    def sync_admin_cookie
-      if current_admin_user
-        cookies[:is_admin] = { value: "1", httponly: false, same_site: :lax, path: "/" }
-      elsif cookies[:is_admin]
-        cookies.delete(:is_admin, path: "/")
-      end
-    end
-  end
-end

apps/api/config/initializers/warp_engine.rb

@@ -6,6 +6,8 @@ Rails.application.config.to_prepare do
 
     c.image_class_name = "Image"
 
+    c.site_url = Rails.configuration.x.site_url
+
     c.ci_adapter = WarpEngine::CI::Woodpecker::Adapter.new(
       url:            ENV["WOODPECKER_URL"],
       api_token:      ENV["WOODPECKER_API_TOKEN"],