feat(11-01): add the conga job framework on River with transactional dispatch

- Pin River v0.47.0 (riverdatabasesql, rivertype) and tidy the example modules
- lagoon.Migrate runs the summercms.conga set: River schema v7 and summer_jobs
  with the apparatus columns plus an internal river_job_id link
- conga.Manager.Dispatch writes the summer_jobs row (status IN_PROGRESS) and the
  River job on the caller's *sql.Tx; a rollback leaves neither
- conga.Job wraps typed job functions so plugins never import River
- conga.StartWorker runs one client on riverdatabasesql.NewWithPgxListener with
  a single-connection LISTEN pool; the final failed attempt sets ERROR
- TestListenPickupLatency: 30s poll, pickup under 1s; poll-only control 2s miss

modules/lagoon/migrations.go

@@ -57,8 +57,9 @@ func migrator(gdb *gorm.DB, pluginID string, migrations []*gormigrate.Migration)
 	}, migrations), nil
 }
 
-// Migrate runs the framework-owned system_files and backend-admin sets
-// first, then each plugin's HasMigrations set in party.Activate order.
+// 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.
 func Migrate(gdb *gorm.DB, plugins []party.Plugin) error {
 	if gdb == nil {
 		return fmt.Errorf("lagoon: gorm db is nil")
@@ -77,6 +78,17 @@ func Migrate(gdb *gorm.DB, plugins []party.Plugin) error {
 	if err := admin.Migrate(); err != nil {
 		return fmt.Errorf("lagoon: migrate backend admin: %w", err)
 	}
+	sqlDB, err := gdb.DB()
+	if err != nil {
+		return fmt.Errorf("lagoon: migrate queue: %w", err)
+	}
+	queue, err := migrator(gdb, QueueHistoryID, QueueMigrations(sqlDB))
+	if err != nil {
+		return err
+	}
+	if err := queue.Migrate(); err != nil {
+		return fmt.Errorf("lagoon: migrate queue: %w", err)
+	}
 	for _, p := range plugins {
 		hm, ok := p.(pact.HasMigrations)
 		if !ok {