Update tests and database index for district_nces_id to fix RuboCop and API response expectations.

Author: Mohamed Ali

app/models/school.rb

@@ -17,7 +17,7 @@ class School < ApplicationRecord
   validates :municipality, presence: true
   validates :country_code, presence: true, inclusion: { in: ISO3166::Country.codes }
   validates :reference, uniqueness: { case_sensitive: false, allow_nil: true }, presence: false
-    validates :district_nces_id, uniqueness: { allow_nil: true }, presence: false
+  validates :district_nces_id, uniqueness: { allow_nil: true }, presence: false
   validates :creator_id, presence: true, uniqueness: true
   validates :creator_agree_authority, presence: true, acceptance: true
   validates :creator_agree_terms_and_conditions, presence: true, acceptance: true

db/migrate/20251121101546_make_district_nces_id_unique.rb

@@ -0,0 +1,6 @@
+class MakeDistrictNcesIdUnique < ActiveRecord::Migration[7.2]
+  def change
+    remove_index :schools, :district_nces_id
+    add_index :schools, :district_nces_id, unique: true
+  end
+end

db/schema.rb

@@ -17,7 +17,9 @@
   end
 
   it "includes the school details and user's roles in the JSON" do
-    school_json = school.to_json(only: %i[id name website reference address_line_1 address_line_2 municipality administrative_area postal_code country_code code verified_at created_at updated_at])
+    school_json = school.to_json(only: %i[
+      id name website reference address_line_1 address_line_2 municipality administrative_area postal_code country_code code verified_at created_at updated_at district_name district_nces_id
+    ])
     expected_data = JSON.parse(school_json, symbolize_names: true).merge(roles: ['owner'], import_in_progress: school.import_in_progress?)
 
     get('/api/school', headers:)