refactor(bootstrap): move runtime init from router to cmd layer

Extract SyncEvents and InitLogWriter from router.Serve into bootstrap.Init
called from cmd entry points with trace-aware context. Preserve existing
Register* wiring for task and push domain integrations.

internal/cmd/bootstrap.go

@@ -0,0 +1,17 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package cmd
+
+import (
+	"context"
+
+	"github.com/Rain-kl/Wavelet/internal/bootstrap"
+	"github.com/Rain-kl/Wavelet/pkg/trace"
+)
+
+func runBootstrap(opts bootstrap.Options) {
+	ctx, span := trace.Start(context.Background(), "bootstrap.Init")
+	defer span.End()
+	bootstrap.Init(ctx, opts)
+}