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

internal/build/stubs/artifacts.tmpl

@@ -66,8 +66,8 @@ package jobs
 
 import (
 	"context"
-	"fmt"
 
+	"git.golem15.com/golem15/summercms/modules/conga"
 	"git.golem15.com/golem15/summercms/modules/pact"
 )
 
@@ -76,17 +76,12 @@ type {{.Ident}}Args struct{}
 
 func ({{.Ident}}Args) Kind() string { return {{printf "%q" .Kind}} }
 
-type {{.Worker}} struct{}
-
-func ({{.Worker}}) Work(ctx context.Context, args pact.JobArgs) error {
-	if _, ok := args.({{.Ident}}Args); !ok {
-		return fmt.Errorf("jobs: unexpected args type %T", args)
-	}
-	return nil
-}
-
 // {{.Func}} returns the {{.Kind}} job.
-func {{.Func}}() pact.Job { return {{.Worker}}{} }
+func {{.Func}}() pact.Job {
+	return conga.Job(func(ctx context.Context, args {{.Ident}}Args) error {
+		return nil
+	})
+}
 {{end}}
 
 {{define "admin_controller.go"}}// Code generated by summer make. DO NOT EDIT.