Validate new Patient foreign key relationships

After adding "cascade on delete" to these `Patient`
FK relationships, we need to validate them.

We can't do this as part of the same migration because it's likely to
cause a long table lock, which is unacceptable in production. Hence,
this needs to be included in the subsequent release.

Jira-Issue: MAV-7065

Author: alistair-white-horne-tng

db/migrate/20260420122440_validate_patient_foreign_keys.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+class ValidatePatientForeignKeys < ActiveRecord::Migration[8.1]
+  TABLES_TO_CASCADE = %w[
+    notify_log_entries
+    school_move_log_entries
+    patient_merge_log_entries
+    pds_search_results
+    patient_programme_vaccinations_searches
+  ].freeze
+
+  def change
+    TABLES_TO_CASCADE.each { |table| validate_foreign_key table, "patients" }
+  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[8.1].define(version: 2026_04_20_101139) do
+ActiveRecord::Schema[8.1].define(version: 2026_04_20_122440) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_catalog.plpgsql"
   enable_extension "pg_trgm"
@@ -1150,7 +1150,7 @@
   add_foreign_key "notes", "users", column: "created_by_user_id"
   add_foreign_key "notify_log_entries", "consent_forms"
   add_foreign_key "notify_log_entries", "parents", on_delete: :nullify
-  add_foreign_key "notify_log_entries", "patients", on_delete: :cascade, validate: false
+  add_foreign_key "notify_log_entries", "patients", on_delete: :cascade
   add_foreign_key "notify_log_entries", "users", column: "sent_by_user_id"
   add_foreign_key "notify_log_entry_programmes", "notify_log_entries", on_delete: :cascade
   add_foreign_key "parent_relationships", "parents"
@@ -1159,10 +1159,10 @@
   add_foreign_key "patient_changesets", "patients"
   add_foreign_key "patient_locations", "locations"
   add_foreign_key "patient_locations", "patients"
-  add_foreign_key "patient_merge_log_entries", "patients", on_delete: :cascade, validate: false
+  add_foreign_key "patient_merge_log_entries", "patients", on_delete: :cascade
   add_foreign_key "patient_merge_log_entries", "users"
   add_foreign_key "patient_programme_statuses", "patients", on_delete: :cascade
-  add_foreign_key "patient_programme_vaccinations_searches", "patients", on_delete: :cascade, validate: false
+  add_foreign_key "patient_programme_vaccinations_searches", "patients", on_delete: :cascade
   add_foreign_key "patient_registration_statuses", "patients", on_delete: :cascade
   add_foreign_key "patient_registration_statuses", "sessions", on_delete: :cascade
   add_foreign_key "patient_specific_directions", "patients"
@@ -1173,13 +1173,13 @@
   add_foreign_key "patient_teams", "teams", on_delete: :cascade
   add_foreign_key "patients", "locations", column: "gp_practice_id"
   add_foreign_key "patients", "locations", column: "school_id"
-  add_foreign_key "pds_search_results", "patients", on_delete: :cascade, validate: false
+  add_foreign_key "pds_search_results", "patients", on_delete: :cascade
   add_foreign_key "pre_screenings", "locations"
   add_foreign_key "pre_screenings", "patients"
   add_foreign_key "pre_screenings", "users", column: "performed_by_user_id"
   add_foreign_key "reporting_api_one_time_tokens", "users"
   add_foreign_key "school_move_log_entries", "locations", column: "school_id"
-  add_foreign_key "school_move_log_entries", "patients", on_delete: :cascade, validate: false
+  add_foreign_key "school_move_log_entries", "patients", on_delete: :cascade
   add_foreign_key "school_move_log_entries", "teams"
   add_foreign_key "school_move_log_entries", "users"
   add_foreign_key "school_moves", "locations", column: "school_id"