feat(modules): wire registry into server startup

Add modules.Registry and config.Config fields to Server struct.
Create registry in main.go, load state from YAML+DB, log all
module states at startup.

Conditionally start job/runner sweeper goroutines only when the
jobs module is enabled.

Update all 5 test files to pass registry to NewServer.

Ref #95, #96

internal/api/dag_handlers_test.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/go-chi/chi/v5"
 	"github.com/kindredsystems/silo/internal/db"
+	"github.com/kindredsystems/silo/internal/modules"
 	"github.com/kindredsystems/silo/internal/schema"
 	"github.com/kindredsystems/silo/internal/testutil"
 	"github.com/rs/zerolog"
@@ -29,6 +30,7 @@ func newDAGTestServer(t *testing.T) *Server {
 		nil, nil, nil, nil, nil,
 		broker, state,
 		nil, "",
+		modules.NewRegistry(), nil,
 	)
 }