refactor(bootstrap): 引入解耦的全局生命周期管理器以隔离业务停机钩子

- 新建 internal/lifecycle 包，提供全局线程安全的 Shutdown 钩子注册与调度能力。
- 在 chwriter 与 risk_control 初始化阶段通过 OnShutdown 将其 Stop 函数注册到管理器中。
- bootstrap.Stop() 函数仅委托调用 lifecycle.Stop()，不再硬编码引入业务包，防止后续框架同步产生合并冲突。

internal/bootstrap/bootstrap.go

@@ -13,6 +13,7 @@ import (
 	"github.com/Rain-kl/Wavelet/internal/apps/admin/push/custom_events"
 	"github.com/Rain-kl/Wavelet/internal/apps/openflare/chwriter"
 	"github.com/Rain-kl/Wavelet/internal/apps/risk_control"
+	"github.com/Rain-kl/Wavelet/internal/lifecycle"
 	taskhandlers "github.com/Rain-kl/Wavelet/internal/task/handlers"
 	"github.com/Rain-kl/Wavelet/pkg/logger"
 )
@@ -91,12 +92,7 @@ func Init(ctx context.Context, opts Options) {
 
 // Stop stops all batch writers and background resources.
 func Stop(ctx context.Context) {
-	if err := risk_control.StopLogWriter(ctx); err != nil {
-		logger.ErrorF(ctx, "[Bootstrap] stop risk_control log writer failed: %v", err)
-	}
-	if err := chwriter.Stop(ctx); err != nil {
-		logger.ErrorF(ctx, "[Bootstrap] stop chwriter failed: %v", err)
-	}
+	lifecycle.Stop(ctx)
 }
 
 // ResetInitRuntimeOnceForTest clears initRuntimeOnce so Init can run again in unit tests.