Refactor Notices and System Health pane (#24243)

* refactor notices

* show startup message for enrichments in health pane

* tweaks

web/e2e/fixtures/mock-data/stats.ts

@@ -16,6 +16,7 @@ function cameraStats(_name: string) {
     pid: 102,
     process_fps: 5.0,
     skipped_fps: 0,
+    skipped_pct: 0,
     connection_quality: "excellent" as const,
     expected_fps: 5,
     reconnects_last_hour: 0,
@@ -75,6 +76,7 @@ export const BASE_STATS = {
     uptime: 86400,
     latest_version: "0.15.0",
     version: "0.15.0-test",
+    retention_unmet: false,
   },
   camera_fps: 15.0,
   process_fps: 15.0,