feat(11-01): run job workers in serve and queue:work, add queue:clear

- Manager gains the apparatus JobManager surface: StartJob, UpdateJobState,
  UpdateMetadata, FailJob, CancelJob (is_canceled + STOPPED + River JobCancel),
  StopJob (STOPPED only), CheckIfCanceled and GetMetadata, all raw column
  writes so updated_at is untouched
- serve starts the in-process worker unless queue.work_in_serve is false and
  stops it on shutdown; an app without jobs gets an idle worker
- queue:work runs a foreground worker with repeatable --queue filters;
  queue:clear deletes available, scheduled and retryable jobs of one queue
- the generated main appends conga.RuntimeCommands; summer delegates
  queue:work and queue:clear; make:job scaffolds a conga.Job

cmd/summer/main.go

@@ -42,6 +42,8 @@ func toolCommands() []bonfire.Command {
 		delegateRollbackCommand(),
 		delegateCommand("migrate:status", "Show per-plugin migration history in the app binary"),
 		delegateCommand("serve", "Run the app HTTP server"),
+		delegateQueueWorkCommand(),
+		delegateCommand("queue:clear", "Clear pending queued jobs in the app binary"),
 	}
 }