Add a notice registry and System Health tab (#24178)

* add a notice registry and System Health tab

Problems Frigate detects on its own (ffmpeg crash loops, stuck detectors, failed model downloads, recordings deleted before their retention period) only ever existed as log lines. This adds a `NoticeRegistry` in the main process backed by two tables, an `update_notice` IPC topic so producers in other processes can reach it through the dispatcher, an admin-only API and websocket topic, and a Health tab that lists them. Kinds declare their own mode, severity, and category in one place: state notices are resolved by their producer, event notices are dismissed by the user.

* treat a prerelease as behind its final release

* fix notices clearing early

* rename menu items and update docs

* don't resolve the update notice on a failed version lookup

web/src/views/system/HealthMetrics.tsx

@@ -0,0 +1,9 @@
+import NoticesPane from "@/components/health/NoticesPane";
+
+export default function HealthMetrics() {
+  return (
+    <div className="scrollbar-container mt-4 flex size-full flex-col gap-4 overflow-y-auto">
+      <NoticesPane />
+    </div>
+  );
+}