The disk-plugin door now scans two Electron-local roots through one
pipeline: the standalone <HERMES_HOME>/desktop-plugins/<name>/plugin.js
door, and <HERMES_HOME>/plugins/<name>/desktop/plugin.js — the desktop
half of a regular agent-plugin package. A feature that needs both SDKs
ships as one installable folder instead of two co-dependent plugins.
Records are keyed by entry-file path (folder names can collide across
roots), each root gets its own fs watch with the poll staying alive
until every root is covered, and older Electron shells without the new
agentPluginsRoot resolver simply skip the unified root.
