[Improve] Keep task supervision Session-scoped

[roomote-roomote]

​Opened on behalf of @mrubens. View the task or mention @roomote-roomote for follow-up asks.

What changed

• Remove elapsed-time stale-silence enforcement for both delegated and direct chat-backed tasks, including the seven-minute runtime threshold, activity/reminder state, and overdue pre/post-tool responses.
• Remove timed-progress guidance from parent-report and direct chat-reply tool descriptions and from Slack, Discord, Teams, and Telegram task instructions.
• Retain the hook as an event-driven lifecycle safeguard for initial acknowledgement, automation reply policy, parent-only posting restrictions, terminal delivery-failure handling, and post-closeout work tracking used by terminal completion enforcement.

Why this change was made

PR #2471 moved coding-work supervision to one Session-scoped follow-through check. Keeping any task-local elapsed-time cadence, including direct-task reminders, duplicates that ownership and can produce redundant updates.

Impact

Tasks no longer interrupt work solely because time elapsed without a message. The parent Session owns ongoing supervision, while task-local acknowledgement, required-input, failure-delivery, clarification, and terminal correctness behavior remains enforced.

[roomote-community]

No code issues found. See task

_{Reviewed ce555b8}

[roomote-roomote]

Removed task-local elapsed-time silence supervision for both delegated and direct chat tasks while preserving the event-driven acknowledgement, automation, subagent-posting, delivery-failure, and stale-closeout safeguards. Focused worker and cloud-agent tests, package typechecks, formatting, lint, and pre-push checks pass in ce555b8.