Set slack_username field separate from usernames

app/jobs/slack_username_update_job.rb

@@ -22,6 +22,7 @@ class SlackUsernameUpdateJob < ApplicationJob
 
         user.username = user_data.dig("user", "profile", "username")
         user.username ||= user_data.dig("user", "profile", "display_name_normalized")
+        user.slack_username = user_data.dig("user", "profile", "username")
         user.slack_avatar_url = user_data.dig("user", "profile", "image_192") || user_data.dig("user", "profile", "image_72")
         user.save!
       rescue => e

app/models/user.rb

@@ -206,6 +206,7 @@ class User < ApplicationRecord
 
     user.username ||= user_data.dig("user", "profile", "username")
     user.username ||= user_data.dig("user", "profile", "display_name_normalized")
+    user.slack_username = user_data.dig("user", "profile", "username")
     user.slack_avatar_url = user_data.dig("user", "profile", "image_192") || user_data.dig("user", "profile", "image_72")
 
     user.parse_and_set_timezone(user_data.dig("user", "tz"))
@@ -299,6 +300,7 @@ class User < ApplicationRecord
 
   def display_name
     return username if username.present?
+    return github_username if github_username.present?
 
     # "zach@hackclub.com" -> "zach (email sign-up)"
     email = email_addresses&.first&.email

db/migrate/20250319193636_add_slack_username_to_users.rb

@@ -0,0 +1,5 @@
+class AddSlackUsernameToUsers < ActiveRecord::Migration[8.0]
+  def change
+    add_column :users, :slack_username, :string
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2025_03_19_165910) do
+ActiveRecord::Schema[8.0].define(version: 2025_03_19_193636) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_catalog.plpgsql"
 
@@ -248,6 +248,7 @@ ActiveRecord::Schema[8.0].define(version: 2025_03_19_165910) do
     t.string "github_avatar_url"
     t.text "github_access_token"
     t.string "github_username"
+    t.string "slack_username"
     t.index ["slack_uid"], name: "index_users_on_slack_uid", unique: true
     t.index ["timezone"], name: "index_users_on_timezone"
   end