MCP server: coordination tools

Features

• MCP server: coordination tools
• Docs: empty-state guidance for contacts and segments list
• Docs: send velocity response shape including hourlyTrend array

Fixes

• Contacts: strip tenant_id from API responses
• CLI: resolve base URL from target profile in signup/login/init
• Reputation and templates endpoints: return camelCase field names
• Reputation recalculate: only counts accepted/sent sends
• Lists: update send --yes help text and improve non-interactive detection
• CLI: remove subscribers|members pipe alias from help text