feat: add AgentLair integration

[piiiico]

What this adds

An AgentLair integration for Agent Orchestrator — connecting orchestrated agent teams to external callers via a persistent @agentlair.dev inbox address.

External systems (CI pipelines, agents from other teams, human operators) can send tasks to your agent team without needing Orchestrator credentials or access.

Files

File	Purpose
secrets-template.yaml	SecretStore template for the AgentLair API key
trigger-inbox-message.yaml	Webhook trigger — fires when a new message arrives
step-template-check-inbox.yaml	Polling alternative: fetch unread inbox messages
step-template-send-reply.yaml	Reply step — close the loop with the caller when work is done
README.md	Setup guide and architectural overview

Pattern

External caller                   │  Your Orchestrator team
──────────────────────────────────┼─────────────────────────────────
CI pipeline sends task            │
  → review-team@agentlair.dev     │  webhook fires → handle-external-task
                                  │    → agents coordinate internally
Agent sends result back           │  agentlair-reply step fires
  ← structured reply thread       │    → caller knows work is complete

No Orchestrator credentials needed on the external side. The AgentLair address is the stable boundary.

Related

The integration files were developed in piiiico/orchestrator-agentlair. This PR brings them into the official integrations registry.