MCP server: journey and segment tools

Features

• MCP server: journey and segment tools
• MCP server: analytics tools (fatigue_score, send_velocity, deliverability, check_reputation)
• Inbound: normalize Gmail +aliases for thread matching
• CLI: billing activate-free command
• Blog: Multi-Provider Failover - Never Depend on One ESP
• Docs: segment filter operators, fields, and behavioral window structure
• Docs: clarify segment-check vs segments-contact and mark required params
• Docs: follow-up section on threads page
• Docs: fill template docs gaps - variables schema, ID vs slug, flag interaction
• Docs: clarify subscribers/members alias in lists page

Fixes

• Billing: prevent duplicate Stripe subscriptions on checkout retry
• Lists: remove {status, message, data} wrapper from lists commands
• Lists: fix 500 from UUID column rejecting template slugs in lists send
• Send: sanitize HTML errors and add shorthand to send simulate
• Send: validate --recipients is a JSON array before processing
• Threads: mark delay flags as required in threads followup help
• Docs: clarify threads followup takes requestId (not threadId)
• Docs: clarify templateId accepts slugs, not just IDs
• Docs: email format validation guidance for --to and recipientEmail
• Docs: next-step guidance on billing status