fix(radio): reject null-body and out-of-range mirror statuses instead of crashing

fetchPinnedRadioResponse built `new Response(stream, { status })` inside
the raw https response callback, which runs outside the surrounding
promise. A Radio Browser mirror answering 204, 205 or 304 (null-body
statuses), or any status outside 200-599, made the Response constructor
throw. Nothing caught it, so the whole dev/preview server process exited
and every layer went down, not only radio. The catalog's mirror failover
never saw the error.

Mirror the guard local-receivers.js already uses: null-body statuses get
a null body, statuses outside 200-599 are rejected, and anything thrown
in the callback rejects the promise so the existing error handling and
mirror failover run.

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+- A Radio Browser mirror answering 204, 205 or 304, or a status outside
+  200–599, no longer crashes the local dev/preview server. Null-body statuses
+  get an empty body; anything else that cannot become a response fails that
+  mirror so the next one is tried.
+
 - Treat explicitly current, complete empty vessel coverage as a successful update,
   clearing obsolete contacts while retaining stale or incomplete snapshots.