When the agent waits for dangerous-command approval, the typing
indicator (_keep_typing loop) kept refreshing. On Slack's Assistant
API this is critical: assistant_threads_setStatus disables the
compose box, preventing users from typing /approve or /deny.
- Add _typing_paused set + pause/resume methods to BasePlatformAdapter
- _keep_typing skips send_typing when chat_id is paused
- _approval_notify_sync pauses typing before sending approval prompt
- _handle_approve_command / _handle_deny_command resume typing after
Benefits all platforms — no reason to show 'is thinking...' while
the agent is idle waiting for human input.