feat(12.2-01): add deferred bindings, guarded upload store and purge

- deferred_bindings migration set under summercms.deferred with backend_user_id
- lagoon.DeferredBind/Unbind/Bindings/Forget/Slaves scoped by DeferredKey
- lagoon.PurgeDeferred with SKIP LOCKED batches and after-commit blob deletes
- attach.Store with the ported image guard, extension and MIME limits
- attach.Relation, attach.HasRelations, attach.BlobKeys, File.ThumbKey
- lagoon README and attachments docs

modules/lagoon/migrations.go

@@ -57,9 +57,10 @@ func migrator(gdb *gorm.DB, pluginID string, migrations []*gormigrate.Migration)
 	}, migrations), nil
 }
 
-// Migrate runs the framework-owned system_files, backend-admin and job-queue
-// (QueueMigrations) sets first, then each plugin's HasMigrations set in
-// party.Activate order.
+// Migrate runs the framework-owned system_files, backend-admin,
+// deferred-binding (DeferredBindingMigrations, history DeferredHistoryID) and
+// job-queue (QueueMigrations) sets first, then each plugin's HasMigrations set
+// in party.Activate order.
 func Migrate(gdb *gorm.DB, plugins []party.Plugin) error {
 	if gdb == nil {
 		return fmt.Errorf("lagoon: gorm db is nil")
@@ -78,6 +79,13 @@ func Migrate(gdb *gorm.DB, plugins []party.Plugin) error {
 	if err := admin.Migrate(); err != nil {
 		return fmt.Errorf("lagoon: migrate backend admin: %w", err)
 	}
+	deferred, err := migrator(gdb, DeferredHistoryID, DeferredBindingMigrations)
+	if err != nil {
+		return err
+	}
+	if err := deferred.Migrate(); err != nil {
+		return fmt.Errorf("lagoon: migrate deferred bindings: %w", err)
+	}
 	sqlDB, err := gdb.DB()
 	if err != nil {
 		return fmt.Errorf("lagoon: migrate queue: %w", err)