The merge adds a test isolation script (`scripts/check-test-isolation.mjs`) to filter runtime noise from live Fusion app paths, fixes MailboxModal spacing by replacing hardcoded values with design tokens (FN-3585), and documents post-install plugin capabilities in the plugin management guide (FN-358
Fusion-Task-Id: FN-3585
This merge adds a complete plugin management system to Fusion: a new `fn plugin` CLI command for installing/removing plugins, a plugin loader in core, a plugin runner in engine, and dashboard routes for plugin management UI, along with a plugin management guide in docs. It also documents task evalua
Fusion-Task-Id: FN-3565
