api.host.features.sidePanel now says whether this plugin may offer the
app-side-panel (ui:side-panel granted), not only that the webmail has
it. A plugin enabled before an update added the permission can then say
so instead of offering a switch that does nothing. The host computes the
assistant's flags per plugin for a frame's init and for each push.
plugin-host-features.test.ts: the host bridge assertions take the
assistant's flags as the test plugin sees them (it lacks ui:side-panel,
so sidePanel is false there).
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