autoresearch iter 22: delete lint suppressions that suppress nothing

24 of the 96 nolint directives were dead: they covered findings that no
longer exist. A stale suppression is not inert — it silently claims any
future finding for that linter in that scope, so a real problem raised
there would vanish without anyone noticing. Explanatory prose was kept as
ordinary comments.

Two directives proved load-bearing under the project gate even though
nolintlint reported them unused, and removing them exposed verified
contextcheck false positives: App.Run does forward a sigCtx derived from
the caller's context to Start, and the migration lock renewal must keep
its own deadline because the task context may already be canceled. Both
were restored, narrowed to the live linter, and given the reason the
originals lacked.

backend/plugins/drivers/driver_asynq_worker/handler.go

@@ -7,7 +7,7 @@ import "context"
 
 // TaskResult 任务执行结果
 //
-//nolint:revive // TaskResult 保留完整名称以避免与通用 Result 混淆
+// TaskResult 保留完整名称以避免与通用 Result 混淆
 type TaskResult struct {
 	Message string // 结果摘要，如 "共清理 120 个文件，耗时 3.2s"
 	Detail  string // 可选的详细结果 JSON
@@ -26,7 +26,7 @@ type PayloadValidator interface {
 // 开发者只需实现 Execute 方法编写业务逻辑，在方法内通过 driver_asynq_worker.AppendLog(ctx, ...) 追加执行日志。
 // 任务的创建、状态更新、错误记录、重试计数全部由框架透明处理。
 //
-//nolint:revive // TaskHandler 保留完整名称以避免与通用 Handler 混淆
+// TaskHandler 保留完整名称以避免与通用 Handler 混淆
 type TaskHandler interface {
 	// Execute 执行任务业务逻辑
 	//   - ctx: 已注入 Trace Span 和 taskID 的上下文