Suprnova v4.2.1

Added

• Add a source to a preset's Content-Security-Policy (#156).
  SecurityHeaders::csp_source(directive, source) and
  ContentSecurityPolicy::with_source(directive, source) add one source to a
  directive of the policy from_env selected, keeping the preset, its
  report-only mode and its reporting origins. A directive the policy leaves
  out starts from the sources it falls back to. An application that allows an
  analytics host in connect-src no longer copies the preset's policy string.
• Stream hooks in every Inertia kit. New React, Vue and Svelte applications
  get frontend/src/lib/stream/, Suprnova's own client for the responses
  HttpResponse::stream_bytes, stream_json and event_stream send:
  useStream, useJsonStream, useEventStream and useJsonEventStream, with
  the names, options and results of Laravel's stream packages. They send the
  CSRF token from the root template's meta tag or the XSRF-TOKEN cookie, and
  cancel their request when the component unmounts. An existing application
  can copy the two files from a new scaffold of its kit.

Fixed

• View::share reaches the Inertia root template (#157). The root
  template rendered without the data shared with every view, so a value
  shared with View::share or View::share_for_request never reached it,
  where Laravel's shared data reaches app.blade.php. It now reads them with
  Askama's value filter, as other views do:
  {% if let Ok(domain) = "plausible_domain"|value::<String> %}. Keep such a
  read inside the if let unless every deployment shares the value, since a
  missing value fails the render.