#89 feat(hn-monitor): unify Slack + Telegram into single dual-transport agent

Summary

Replaces the separate hn-monitor and hn-monitor-telegram agents with a single dual-transport agent. Delivers to Slack, Telegram, or both — configuration-driven via SLACK_CHANNEL and TELEGRAM_CHAT inputs (both optional).

Depends on workforce#250 for @agentworkforce/delivery (now published as ^0.1.0).

Changes

• Single agent.ts — uses createDelivery from @agentworkforce/delivery, auto-detects configured transports
• Non-blocking parentRef threading — header published with 0ms timeout, body threaded via parentRef (x-reply-radar pattern, zero receipt round-trips)
• Backported Telegram improvements: fetchWithTimeout (8s AbortController), withTimeout for LLM, pending thread body recovery with headerRefs for proper retry threading
• Shared helpers (input, list, withTimeout, fetchWithTimeout) from @agentworkforce/delivery
• Persona declares both slack and telegram integrations, both inputs optional: true
• Q&A routes relay inbox DMs and Telegram messages through shared handler, replies only to origin transport
• Recovery tests verify pending body retry preserves threading context
• Removed hn-monitor-telegram/ directory (now superseded)
• 161/161 tests pass, typecheck clean

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Summary by cubic

Unifies the Slack and Telegram HN monitors into one agent that posts to Slack, Telegram, or both via @agentworkforce/delivery. Adds non-blocking threading with robust recovery and prevents cross-post or partial-publish failures.

• New Features

  • Config via SLACK_CHANNEL and TELEGRAM_CHAT (optional) with unified, non-blocking parentRef threading; adds fetchWithTimeout (8s) and withTimeout to prevent hangs.
  • Durable recovery: saves headerRefs and retries threaded bodies on the next scan; unified Q&A for relay DMs and Telegram, replying only on the origin transport.

• Bug Fixes

  • Treats partial header publishes as failures; builds pending state before sending the body; clears orphaned pending bodies when targets change; fixes cross-post leakage with transport-scoped delivery.
  • Removes hn-monitor-telegram/ and superseded Telegram tests; updates imports; uses published @agentworkforce/delivery@^0.1.0 (matches main).