fix(tasks): claim the teardown report before the producer cancel runs

A throwing producer cancel jumped to the force-fail branch before
`reported` was set, so `settle()` announced an unreported completion and
the default wakeup delivery started a model turn on an owner the host
was already destroying — the exact failure mode marking the record
reported exists to prevent.

Teardown claims the report before calling the producer, because that
decision does not depend on whether the producer's cancel succeeds.

Also reject a `maxConsecutiveWakes` that cannot bound anything: the
field exists to cap a runaway chain, and `Infinity` removed the cap
while a fraction never named a turn.

Correct the module JSDoc and the background-task runtime note, both of
which still promised that notices never wake an idle agent.

packages/tasks/tasks-local/src/index.ts

@@ -466,14 +466,17 @@ export class LocalTaskService extends TaskService {
   private cancelForTeardown(tasks: TrackedTask[], reason: string): void {
     for (const task of tasks) {
       if (isTerminal(task.status)) continue
+      // Teardown cancellation is a kill without a caller, so it claims the
+      // terminal report the same way `kill()` does. Nothing will read a notice
+      // for a task whose owner or service is being destroyed, and a waking
+      // reporter would spend a model request per teardown layer. This is
+      // decided before the producer runs: the force-failure below settles the
+      // record too, so a throwing cancel must not be the one path that
+      // announces an unreported completion into a disposing owner.
+      task.reported = true
       try {
         task.cancel(reason)
         task.status = 'stopping'
-        // Teardown cancellation is a kill without a caller, so it claims the
-        // terminal report the same way `kill()` does. Nothing will read a
-        // notice for a task whose owner or service is being destroyed, and a
-        // waking reporter would spend a model request per teardown layer.
-        task.reported = true
         // Teardown reaches settlement only after the producer releases, which a
         // slow stop can defer; announcing the transition here is what keeps an
         // observer from showing `running` for that whole window.