Use request-local stream silence for the waiting notice, preserving quiet
activity heartbeats and all existing watchdog policies. Distinguish a stream
that stopped from a request with no response, and clear this request's notice
on the next poll when events resume. Existing fresh first-event retry phases
also reset the display; recovery deadlines explicitly use total call elapsed.
Add two invariant tests (eight cases), proven red on main, plus EN/ZH docs.
Local SDK SSE through classic CLI callbacks in a PTY verifies active reasoning,
true silence, and an already-visible warning clearing on resumed reasoning.
Related: #92657 addresses repeated waiting notices; its phase deduplication
still labels active streams as no response and is not incorporated here.
Teknium