DEV: Move discourse-chat to the core repo. (#18776)

As part of this move, we are also renaming `discourse-chat` to `chat`.

plugins/chat/lib/discourse_dev/public_channel.rb

@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+require "discourse_dev/record"
+require "faker"
+
+module DiscourseDev
+  class PublicChannel < Record
+    def initialize
+      super(::CategoryChannel, 5)
+    end
+
+    def data
+      chatable = Category.random
+
+      {
+        chatable: chatable,
+        description: Faker::Lorem.paragraph,
+        user_count: 1,
+        name: Faker::Company.name,
+        created_at: Faker::Time.between(from: DiscourseDev.config.start_date, to: DateTime.now),
+      }
+    end
+
+    def create!
+      super do |channel|
+        Faker::Number
+          .between(from: 5, to: 10)
+          .times do
+            if Faker::Boolean.boolean(true_ratio: 0.5)
+              admin_username =
+                begin
+                  DiscourseDev::Config.new.config[:admin][:username]
+                rescue StandardError
+                  nil
+                end
+              admin_user = ::User.find_by(username: admin_username) if admin_username
+            end
+
+            Chat::ChatChannelMembershipManager.new(channel).follow(admin_user || User.new.create!)
+          end
+      end
+    end
+  end
+end