fix(policy): Cascade delete policy when scope is deleted (#5014)

internal/db/schema/migrations/oss/postgres/82/01_storage_policies.up.sql

@@ -6,6 +6,7 @@ begin;
 create table policy (
   public_id wt_public_id primary key,
   scope_id wt_scope_id not null
+  -- constraints replaced in internal/db/schema/migrations/postgres/91/01_storage_policies.up.sql
   constraint policy_scope_id_fkey
     references iam_scope(public_id)
     on delete restrict
@@ -17,6 +18,7 @@ comment on table policy is
 create table policy_storage_policy (
   public_id wt_public_id primary key,
   scope_id wt_scope_id not null
+  -- constraints replaced in internal/db/schema/migrations/postgres/91/01_storage_policies.up.sql
   constraint policy_storage_policy_scope_id_fkey
     references iam_scope(public_id)
     on delete restrict

internal/db/schema/migrations/oss/postgres/91/01_storage_policies.up.sql

@@ -0,0 +1,25 @@
+-- Copyright (c) HashiCorp, Inc.
+-- SPDX-License-Identifier: BUSL-1.1
+
+begin;
+
+  -- replaces constraints from internal/db/schema/migrations/postgres/82/01_storage_policies.up.sql
+  alter table policy 
+    drop constraint policy_scope_id_fkey;
+  alter table policy
+    add constraint policy_scope_id_fkey
+    foreign key (scope_id)
+      references iam_scope(public_id)
+      on delete cascade
+      on update cascade;
+
+  alter table policy_storage_policy 
+    drop constraint policy_storage_policy_scope_id_fkey;
+  alter table policy_storage_policy
+    add constraint policy_storage_policy_scope_id_fkey
+    foreign key (scope_id)
+      references iam_scope(public_id)
+      on delete cascade
+      on update cascade;
+
+commit;

internal/db/sqltest/tests/policy/org_policy_storage_policy.sql

@@ -0,0 +1,30 @@
+-- Copyright (c) HashiCorp, Inc.
+-- SPDX-License-Identifier: BUSL-1.1
+
+begin;
+
+  select plan(6);
+
+  -- create a storage policy
+  prepare insert_policy as
+    insert into policy_storage_policy
+      (public_id,       scope_id,       retain_for_days, delete_after_days)
+    values
+      ('pst_test1234',  'o__foodtruck', 1,               0);
+  select lives_ok('insert_policy');
+
+  select is(count(*), 1::bigint) from policy_storage_policy where public_id = 'pst_test1234';
+  select is(count(*), 1::bigint) from policy where public_id = 'pst_test1234';
+
+  -- deleting org should also delete the storage policy creating in that org
+  prepare delete_org as
+    delete from iam_scope
+     where type = 'org'
+       and public_id = 'o__foodtruck';
+
+  select lives_ok('delete_org');
+
+  select is(count(*), 0::bigint) from policy_storage_policy where public_id = 'pst_test1234';
+  select is(count(*), 0::bigint) from policy where public_id = 'pst_test1234';
+
+rollback;