A platform is named once: WarpEngine::Platform

The list of platforms lived on `PlatformLink::SUPPORTED_PLATFORMS` — a model
about links to a platform's website — and was copied around it four times in
the admin (`%w[tic80 ebitengine love c64 godot bevy phaser]`), spelled out in
three apipie descriptions, and turned into a class name by string
interpolation in three services:

    "WarpEngine::Platforms::#{platform.camelize}::Service".constantize

Seven places that had to agree, and nothing that made them.

`WarpEngine::Platform` is now that one place. `Platform.names` is the list,
`Platform.find!("godot")` answers with a value object that knows its `label`,
its `expected_kinds` and its updater `service`, and the constantize is gone —
the registry holds the reference. `PublishService` and `BuildsService` ask it,
the admin selects read `Platform.names`, and
`PlatformLink::SUPPORTED_PLATFORMS` stays as an alias of `Platform::NAMES` so
a host pinned to 0.7 keeps working.

`Software` also defends its own value sets now. It validated neither `status`
nor `platform`, so a mistyped platform only surfaced later, at publish time,
as "Unsupported platform" — after the row existed. And `status` had three
different answers depending on where you looked: the admin offered
development/demo/released/archived, the API documentation claimed
"active, inactive", and the database holds the first four. `Software::STATUSES`
is the list, the inclusion validations enforce both, and the documentation
names the values the database actually has.

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

lib/warp_engine.rb

@@ -5,6 +5,7 @@ require "apipie-rails"
 
 require "warp_engine/version"
 require "warp_engine/configuration"
+require "warp_engine/platform"
 require "warp_engine/storage"
 require "warp_engine/access"
 require "warp_engine/images"

lib/warp_engine/platform.rb

@@ -0,0 +1,48 @@
+module WarpEngine
+  class Platform
+    NAMES = %w[tic80 ebitengine love c64 godot bevy phaser].freeze
+
+    class << self
+      def names = NAMES
+
+      def all = NAMES.map { |name| new(name) }
+
+      def exists?(name) = NAMES.include?(name.to_s)
+
+      def find(name)
+        return nil unless exists?(name)
+
+        new(name.to_s)
+      end
+
+      def find!(name)
+        find(name) || raise(ArgumentError, "Unsupported platform: #{name}")
+      end
+    end
+
+    attr_reader :name
+
+    def initialize(name)
+      @name = name.to_s
+    end
+
+    def service_class
+      "WarpEngine::Platforms::#{name.camelize}::Service".constantize
+    end
+
+    def service = service_class.new
+
+    def label = service_class.label
+
+    def expected_kinds = service_class.expected_kinds
+
+    def to_s = name
+
+    def ==(other)
+      other.is_a?(Platform) ? name == other.name : name == other.to_s
+    end
+    alias eql? ==
+
+    def hash = name.hash
+  end
+end