Show an ephemeral "agent is working" indicator (thinking/searching/
generating/analyzing…) in Bitrix24 chat while the agent processes, so
users on this non-streaming channel aren't left staring at silence
until the final reply. Send behavior is unchanged; no LLM call, no DB.
Generic layer (internal/channels):
- New optional ActivityIndicatorChannel interface.
- HandleAgentEvent routes run.started->THINKING, tool.call->mapped
status, tool.result->ANALYZING; static tool->status mapping.
- Conditional heartbeat ticker fills LLM-inference gaps (re-sends only
when idle), 5s per-run throttle caps call rate; ticker stopped on
terminal events AND in UnregisterRun (safety net for missed terminals).
Bitrix24 (internal/channels/bitrix24):
- OnActivityEvent calls imbot.v2.Chat.InputAction.notify best-effort,
drop-on-limit (raw Client.Call, no retry) so cosmetic notifies never
steal leaky-bucket capacity from real message sends.
- Per-channel activity_indicator toggle (default on).
Web UI + docs: dashboard toggle, i18n en/vi/zh, channels doc section.
Tests: 26 unit tests incl. UnregisterRun-stops-ticker regression.
