n8n Workflow Design

Design an n8n workflow for this process.

**Process**: {e.g. GitHub issue → Slack → Notion}
**Trigger**: {schedule/webhook/event}
**Systems**: {APIs}
**On failure**: {retry, alert, DLQ}

Output:
1. Flow (mermaid or numbered nodes)
2. Per-node type, I/O, key settings
3. Auth/env var placeholders (no secrets)
4. Error handling and idempotency
5. Phased rollout (MVP first)

Note HTTP Request fallbacks if no native node.