Add phase override to Location model

We will allow users to edit the phase of a school as the information from GIAS is often out-dated/incorrect.
We would still want to track GIAS phase as a source of truth so we add a new column to the model instead of
overriding the existing one.

Author: murugapl

app/models/location.rb

@@ -15,6 +15,7 @@
 #  gias_year_groups          :integer          default([]), not null, is an Array
 #  name                      :text             not null
 #  ods_code                  :string
+#  phase                     :string
 #  position                  :geography        point, 4326
 #  site                      :string
 #  status                    :integer          default("unknown"), not null

db/migrate/20260422100000_add_phase_to_locations.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddPhaseToLocations < ActiveRecord::Migration[8.0]
+  def change
+    add_column :locations, :phase, :string
+  end
+end

spec/factories/locations.rb

@@ -15,6 +15,7 @@
 #  gias_year_groups          :integer          default([]), not null, is an Array
 #  name                      :text             not null
 #  ods_code                  :string
+#  phase                     :string
 #  position                  :geography        point, 4326
 #  site                      :string
 #  status                    :integer          default("unknown"), not null

spec/models/location_spec.rb

@@ -15,6 +15,7 @@
 #  gias_year_groups          :integer          default([]), not null, is an Array
 #  name                      :text             not null
 #  ods_code                  :string
+#  phase                     :string
 #  position                  :geography        point, 4326
 #  site                      :string
 #  status                    :integer          default("unknown"), not null