0.21.0: Activity And Delivery Extension Platform

[llblab]

Summary

This release adds stable target-aware Telegram Delivery and normalized Activity APIs for companion extensions, with public package membranes, lifecycle-safe dispatch, logical message handles, and leader/follower transport support.

It also hardens cross-thread authorization, session replacement, shutdown fencing, partial chunk recovery, compaction identity, Pi 0.80.6 compatibility, and private Guest Mode attribution while keeping index.ts composition-only.

Why

Companion extensions previously had to reach into bridge internals or own Telegram transport to show lifecycle-adjacent UI. The new platform provides narrow supported contracts while preserving pi-telegram's routing, authorization, ordering, and process-ownership boundaries.

User-visible behavior

• Companion extensions can register non-blocking Activity handlers for agent, reasoning, assistant, tool, compaction, and settlement events.
• Extensions can send, edit, delete, and reconcile chunked Telegram views through authorized active-turn, instance, aggregate, or explicit targets.
• Reload/session replacement creates fresh Activity and Delivery generations; stale handlers and handles fail closed.
• Partial multi-chunk failures return recoverable handles for deterministic retry or cleanup.
• Private Guest Mode keeps guest anchored to the remote conversation peer when replying to a bot response.

Changed areas

• api/activity.ts, lib/activity.ts: stable registration, normalization, dispatcher isolation, generation fencing, and Delivery-backed contexts.
• api/delivery.ts, lib/delivery.ts: target policy, rendering/transport adaptation, ordering, logical handles, lifecycle fencing, and partial recovery.
• lib/bus*.ts: explicit authenticated aggregate-delivery marker authorization and stripping.
• lib/lifecycle.ts, lib/bindings.ts, lib/pi.ts: typed Pi 0.80.6 lifecycle mapping and session replacement.
• Docs/package metadata: complete public API contracts, architecture guidance, external demo reference, and version 0.21.0.

Risk Notes

• Activity handler queues intentionally have no hard event-count drop policy; adjacent streaming deltas coalesce and consumers must keep handler work bounded.
• A Telegram request already accepted before shutdown may materialize, but the retiring operation cannot continue or adopt the replacement generation.
• No config migration is required. Pi 0.80.6 or newer is required for the public agent_settled boundary.

Validation

• npm run validate — 1,138 tests; 1,137 passed, 1 platform skip; typecheck passed; audit clean; npm pack dry-run produced llblab-pi-telegram-0.21.0.tgz.
• Domain DAG validator — passed with 0 errors and 0 warnings.
• ABCd context validator — passed with 0 errors and 0 warnings.
• Final multi-lens review and verification — ready; no remaining Activity or Delivery release blocker.