[RUBY-3212] Add unique index to projects name

- Created migration to add unique index to `pafs_core_projects` table on the `name` column.
- Updated schema to reflect the new unique index on the `name` column.

db/migrate/20240904104418_add_unique_index_to_projects_name.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddUniqueIndexToProjectsName < ActiveRecord::Migration[7.2]
+  def change
+    add_index :pafs_core_projects, :name, unique: true
+  end
+end

spec/dummy/db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2024_03_27_113556) do
+ActiveRecord::Schema[7.2].define(version: 2024_09_04_104418) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -328,6 +328,7 @@
     t.integer "earliest_start_year"
     t.string "updated_by_type"
     t.bigint "updated_by_id"
+    t.index ["name"], name: "index_pafs_core_projects_on_name", unique: true
     t.index ["reference_number", "version"], name: "index_pafs_core_projects_on_reference_number_and_version", unique: true
     t.index ["slug"], name: "index_pafs_core_projects_on_slug", unique: true
     t.index ["submitted_to_pol"], name: "index_pafs_core_projects_on_submitted_to_pol"
@@ -398,5 +399,4 @@
     t.index ["reset_password_token"], name: "index_pafs_core_users_on_reset_password_token", unique: true
     t.index ["unlock_token"], name: "index_pafs_core_users_on_unlock_token", unique: true
   end
-
 end