The sandbox runtime copied only the three policy flags from the host's
features, so a flag an assistant area adds (sidePanel, files, ...) never
reached api.host.features and the plugin hid the feature. The runtime
now copies every other flag the host names as true or false.
The host bridge assertions compare against withAssistant(...) like the
snapshot ones already did, because the init payload and host-change
carry the assistant's flags on top of the three policy flags.
The assistant's new host calls come in four areas (context, actions,
Files, the panel in every view), built side by side. Each area gets its
own files under lib/plugin-sandbox/assistant for its permissions, method
table, dispatcher, host feature flags and sandbox methods; the shared
files only read the merged result. No area adds anything yet. The host
features test now compares against the core flags plus the areas' flags.
Linus Rath