[feature] Telegram channel: keep sendChatAction("typing") alive while a turn is in flight

Problem

Today the Telegram channel plugin sends sendChatAction("typing") once on inbound message receipt. Telegram only honors that for ~5 seconds, after which the "… typing" indicator disappears in the user's chat.

For long-running agent turns (browser automation, multi-step tool sequences, anything that takes >5s), the user has no idea whether the agent is still processing or has gone silent / wedged. From the user's perspective, a healthy 30s turn looks identical to a wedged session — both show "no typing indicator, no message yet."

Current behavior

• User sends "do X"
• Channel emits one sendChatAction("typing") → indicator shows for ~5s
• Indicator disappears
• Agent works for another 25s
• Final assistant message arrives

During the silent 25s, the user often re-pings the agent ("are you there?"), assumes it's stuck, or escalates manually (SSH in, restart gateway, etc.).

Proposed behavior

While a turn is in flight (between inbound user message and final assistant reply being delivered), the Telegram channel plugin refreshes sendChatAction("typing") every 4 seconds so the indicator stays continuously visible. Stops on:

• final reply sent
• agent error / timeout
• channel disconnection

Same behavior would help on record_voice / upload_document actions when the agent is generating media, but plain typing covers the 95% case.

Why this matters

• It's the single best signal Telegram gives users that "your message is being processed."
• Without it, every long turn looks like a hang. Users either re-ping (which can confuse the agent's turn machinery) or assume the agent died and restart manually.
• Goose runs browser automation / Maverick runs cron orchestration — both routinely have multi-minute turns. The single 5s typing flash is misleading.

Implementation sketch (open to whatever fits the codebase)

Roughly: when the channel hands an inbound message off to the agent runtime, kick off a setInterval(() => sendChatAction(chatId, "typing"), 4000). Clear the interval when the response is delivered or the turn errors out.

Edge cases worth handling:

• Multiple concurrent turns in different chats → one interval per chat_id
• Network failures on sendChatAction (already seen in Joey's logs as telegram sendChatAction failed: Network request for 'sendChatAction' failed!) shouldn't kill the interval — they should swallow the error and try again on next tick
• Don't fire on cron / silent / --announce-only payloads where there's no upstream user waiting

Reference: existing call site

file: dist/subsystem-bmJ5rL4Q.js (and corresponding source)
subsystem: gateway/channels/telegram
existing: telegram sendChatAction failed: Network request for 'sendChatAction' failed!

So the call already exists — the change is wrapping it in a per-turn interval rather than firing once.

Discord channel

Similar gap probably exists on Discord (channelTyping / MessageTyping indicator also expires after ~10s). Worth applying the same pattern there once the Telegram side is settled.

Filed by user @joeywrightphoto on behalf of his triple-agent setup (Maverick / Goose / Merlin) — running into this multiple times per day on long browser-automation turns.