docs: add Connecting Desktop to Many Hermes Instances guide
New user-guide page for the multi-connection registry (Settings →
Connections): connection kinds + auth table, unique device names, v1
migration, union agent roster with @name-device handles, lazy sockets /
ssh connect-on-demand, fleet-wide updates (cloud excluded), plugin SDK
surface (host.connections/agents/ensureAgent/warmAgent, Bot Mode as
reference consumer), troubleshooting. Registered in sidebars.ts;
cross-linked from desktop.md and multi-profile-gateways.md.
Docusaurus build validated.
Teknium
12859e9eb5