fix(drivers): propagate app-lifetime context through inproc cron/worker drivers

cron 触发与 worker 执行的任务现在继承应用生命周期 context（关闭时级联取消，带超时子上下文），
替代裸 context.Background()。contextcheck 清零。
lint_issues 26→24

backend/plugins/drivers/driver_inproc_worker/plugin.go

@@ -119,8 +119,9 @@ func (p *Plugin) Type() core.DriverType {
 	return core.DriverTypeWorker
 }
 
-// Start initiates task consumption.
-func (p *Plugin) Start(_ context.Context) error {
+// Start initiates task consumption. ctx is the app-lifetime context handed to
+// task executions so shutdown cancellation propagates.
+func (p *Plugin) Start(ctx context.Context) error {
 	if p.queue == nil {
 		p.queue = NewInprocQueue(p.concurrency, p.queueCapacity, p.coreCtx.Tasks())
 	}
@@ -129,7 +130,7 @@ func (p *Plugin) Start(_ context.Context) error {
 	globalQueue = p.queue
 	globalMu.Unlock()
 
-	p.queue.Start()
+	p.queue.Start(ctx)
 	return nil
 }