Adds /api/connectors/call -> connectd /mcp/call, so the app can invoke a connector tool (e.g. WhatsApp
get_pairing_qr / get_login_status for the pairing UI) through the soul, keeping app->soul->connectd
intact (UI never hits connectd directly) and working for future remote/hosted clients. elc-clean.
NOTE: soul-core change — needs dist/soul.c regen (Will), can ride the same rebuild as PR #56.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>